Pdf file reader Archives

Pdf file reader Archives

pdf file reader Archives

pdf file reader Archives

Using PDF/A as a Preservation Format

The PDF/A (or Portable Document Format Archival) is a format designed as a preservation format for digital records, particularly documents. The format, though, can also be used for scanned documents. It is an international standard and a subset of the PDF format. One of the great values of PDF formats is that they are open standards, used widely across the world, and designed to record both images and machine-readable text in one document.

PDF/A can be used to store many types of records, but it is most valuable as a format for storing long-term copies of digital textual documents, such as Microsoft Word files. When you convert such a file into a PDF/A, the resulting file retains the look and feel of the original document. Each page of the original document appears as a single page in the preservation file, the same fonts are used in both documents, and you can search the text of the PDF/A just as you had in the original. If the document is in color, the color is still there as well. For these reasons, PDF/A is a good format in cases where the appearance of the document matters to interpretation and understanding it.

Other digital files may also be converted to PDF/A, including regular PDFs, email, digital images, and spreadsheets. You could even convert a sequence of digital images into one PDF/A. Any digital file that can be printed can be converted to a PDF/A, though this format is better for some documents than others. The format works best for static files that do not change. It is not appropriate for files that are always in flux, such as databases.

Paper documents can also be converted to PDF/A during scanning, but if doing so it will be best if you also use optical character recognition (OCR) software to convert the images of letters in the document into electronic text. Whenever you OCR a document, however, there will be data errors in the converted text. (See the State Archives’ Digital Imaging Guidelines for the guidelines for scanning and OCR’ing textual documents.)

PDF/A has many advantages as a file format for the storage of records with long or permanent retention periods. If you are considering other digital file formats as options for long-term or permanent storage, compare their advantages to those of PDF/A. The advantages of PDF/A given below will serve as a checklist of features necessary in any preservation format. Note that you will find file formats that have one or even a few of these advantages, but it is the accumulation of these that makes PDF/A a good preservation format. Microsoft Word, for instance, is ubiquitous and long-lived, but it is missing other essential features that would make it a candidate for long-term storage of records.

Not platform-dependent

Since its inception, the PDF format has been accessible across computing platforms, and the PDF/A format has this same advantage. What this means is that a PDF/A created in a Windows environment will be perfectly readable and usable in a Mac environment, or vice versa.


Something ubiquitous is something that you can find everywhere, and the PDF and PDF/A formats are used by hundreds of millions of people across the world every day. The value of this universal use of PDF is that this means it is unlikely to die out as a format anytime soon. Also, since PDF/A is merely a subset of PDF, any software product that can read a PDF can read a PDF/A. Adobe distributes for free Adobe Reader software for reading PDFs, allowing everyone to read a PDF/A at no additional cost in computing equipment or hardware. (This is downloadable at pachasnack.com)


The PDF format has been around since , so this format is unlikely to disappear soon. Again, so long as PDF is around, PDF/As will be easy to read and use.

Supporting metadata

To understand a digital file, you often need good metadata to give context to the file. This metadata can include many pieces of information, such as the name of the author and the date of a file. For digital files, metadata is often stored within the file itself, so it is important to be able to save this metadata (and even add to it) when converting one digital file to another. PDF/A is specifically designed to support rich metadata.

Supporting perfect conversion

The goal of any conversion program, even microfilming and scanning, is to create a new record that is as much like the original as possible. PDF/A is designed to do much in this area: It saves the look and searchability of the original file, and it requires that the original fonts, colors, and layout be preserved in the PDF/A you produce. The PDF/A format does this by being self-contained, meaning by saving within the file itself all of the information it needs to display the document. (This includes the fonts and the color definitions, which are not always saved in other file formats.)


An open file format is one in which the specifications are available to anyone and where anyone can use those specifications to develop a software product to create and read the file format. PDF/A has always been a preservation standard since its initial release in , so it clearly meets this criterion.

Supports authenticity

In the digital world, even more so than the analog world, it is important to ensure that records retains that authenticity, that they are not modified after their creation, that they do not come to hold information different than they originally held. No file format alone can ensure authenticity, but PDF/A supports authenticity by being difficult (though not impossible) to modify and by providing document security (such as digital signatures).


All that extensible means is that the readability of a digital file will extend into the future, that a file will not become unreadable as software changes. The PDF/A standard is designed so that the earliest PDF/A will always be readable in the most current PDF viewer. This is assured by the fact that every version of PDF/A is always a subset of the one that comes after it, meaning that the PDF/A-3 standard always supports all the characteristics of the original PDF/A-1—along with a few extra features.

Although PDF/A has many advantages, it has disadvantages as well. All digital files cannot be converted to PDF/A. Sometimes this happens because the files have features that are forbidden from PDF/A because there is no known way to preserve these features over time. Such files include documents with audio and video data or Javascript. PDF/A is also a complex text and image format, and its complexity might become a liability in the future. Finally, some digital files or records are simply not appropriate for conversion to PDF/A. For instance, it is possible to save a website as a PDF/A, but the resulting file would be cumbersome and difficult to use. Since PDF/As require the embedding of any fonts used in the file, they can also be larger than regular PDFs. Despite these drawbacks, over all PDF/A is a good preservation format for most digital documents.

Since PDF/A is designed to be a format that extends its features over time, there are already a number of different versions of PDF/A (PDF/A-1, -2, and -3). Beyond this, each generation of the format has different conformance levels, which indicate the degree to which each meets the highest goals of PDF/A.

All versions of PDF/A are joined together by a certain subset of supported features, which can primarily be boiled down to one idea: each PDF/A file has to be self-contained, holding within itself all the information needed for it to be read as a complete file. It might seem that all digital files are self-contained, that each one carries everything needed to make it readable as it was intended to be read, but this is not the case. For instance, if you work on a Microsoft Word file at work and then open it at home, it may look much different: If you don’t have the same font at home that you have at work, then the Word file will choose the closest font it can find on your computer. A Word file does not have to store the fonts it uses within itself; instead, it stores only information about the font it uses and then searches for that font in whatever computing environment it is in.

A PDF/A, however, must embed all of its fonts within itself, so that it never has to search for the fonts it needs to reveal itself fully to a user. To save space, the file will store only the subset of the font it needs, so if the file does not have a capital X within it, the information to show that character is not stored in the file. PDF/As also need to have unlimited legal use of any embedded fonts, because if they do not then they will not be able to be viewed accurately in the future. Some fonts have metadata within them that will not allow them to be used in a PDF or that limit the timeframe in which the font may be legally used. If such fonts are in a document you are trying to convert to a PDF/A, then you will not be able to produce a PDF/A from it.

Besides embedded fonts, a PDF/A also needs device-independent color, which means that the display of color in a file cannot be dependent on the computing device you used to view it. A PDF/A has to one of two kinds of color encoding to ensure device independence. These two issues, embedded fonts and device-independent color, are part of a larger rule that a PDF/A file cannot have any reference to outside content.

Also essential to the definition of a PDF/A are the metadata requirements. Because PDF/As are archival files, they must include metadata describing the file, and the file must identify itself as a PDF/A of a certain version. Since the file extension for a PDF/A is the same as for any kind of PDF (they are all .pdf), the file must store metadata within itself that identifies precisely what version of PDF/A it is.

PDF/A-1 ()

ISO Standard
Based on PDF Reference (Acrobat 5)

The earliest version of PDF/A is the PDF/A-1, the number one denoting that it is the first in a series. PDF/A-1 also excludes features that are likely to be excluded from the PDF/A series forever or at least for a long time. Since the means of preserving certain content is unknown, no version of PDF/A supports audio or video content, JavaScript or executable files, or 3D modeling, all of which are complex forms of data. Encryption is forbidden in all versions of PDF/A, since it could prove to be a permanent impediment to accessing an archival record.

PDF/A-1 also supports the fewest features of any version of PDF/A. It does not support transparency (which is a feature that supports the creation of text shadowing, since the means of supporting transparency long term had not yet been solved). This version also does not support JPEG compression or embedded files, which are supported in all subsequent versions.

PDF/A-1a conformance level
The highest conformance level of any PDF/A is the 1a level, where the “a” stands for “accessible.” This level has all the general features of a PDF/A but also preserves the document’s logical structure. What this means is that the PDF/A-1a stores information to preserve the text stream (or text streams) of a document in reading order. If you create a PDF/A-1a of a newsletter, for instance, the file will know to direct you from one story on the front page directly to where it continues on the fifth. This feature is especially important for the visually impaired, whose screen readers will understand the metadata in the PDF/A-1a and guide them logically through the file. A PDF/A-1a must also specify within itself the language it is written in, and it must include Unicode mapping. Unicode is an extension to ASCII. Where ASCII encodes all of the Latin alphabet, Unicode encodes all writing systems that have ever existed, which makes for a file with a more accurate representation of text.

PDF/A-1b conformance level
The PDF/A-1b conformance level is a step down from the 1a. (The “b" in this level stands for “basic.”) This level preserves the visual appearance visual format of the files, just as all PDF/As do, but it does not require as much descriptive information, the use of Unicode, the preservation of the reading order of the text stream. This makes PDF/A-1b a less accessible format (for the visually impaired), but it still produces a usable preservation file. Since, all PDF/As in conformance level b are easier to make, these also tend to be more common.

PDF/A-2 ()

ISO Standard
Based on PDF Reference

PDF/A-2 extends the format by supporting a number of different features: the embedding of OpenType fonts (instead of only PostScript fonts), JPEG image compression, transparent objects, and layers (which can be hidden to support the viewing of a multi-layer document). This version also defines use of digital signatures (thus better supporting security), specifies requirements for the creation of metadata by the person creating the PDF/A, and allows the embedding of documents within a PDF/A. In the last case, only PDF/As can be embedded in a PDF/A, but this allows users to create sets of documents in one file (such as a series of emails or related reports).

PDF/A-2a conformance level
This level is the same as PDF/A-1a, but with PDF/A-2 extensions.

PDF/A-2b conformance level
This level is the same as PDF/A-1b, but with PDF/A-2 extensions.

PDF/A-2u conformance level
The PDF/A-2u level is identical to the PDF/A-2b, except in one regard: it requires the use of “Unicode.” (The u stands for Unicode.) As with version 2b, version 2u does not represent the logical structure of the document, but it is a bit better than 2b because it better represents text in multiple writing systems.

PDF/A-3 ()

ISO Standard
Based on PDF Reference

Currently, PDF/A-3 is the latest version of the format, but new versions of PDF/A are expected and inevitable. This newest version includes only one change to the PDF/A-2 version: it allows embedding of any type of file to a PDF/A. The value of this change is that it supports the practice of maintaining the original source file along with the PDF/A created from it. This allows you to maintain both versions as part of one file, thus simplifying your preservation practices, if you are following the recommended digital preservation practice of always retaining the original digital files along with their preservation copies.

PDF/A-3a conformance level
This level is the same as PDF/A-2a, but with PDF/A-3 extension.

PDF/A-3b conformance level
This level is the same as PDF/A-2b, but with PDF/A-3 extension.

PDF/A-3u conformance level
This level is the same as PDF/A-2u, but with PDF/A-3 extension.

Choosing a version of PDF/A to use

A number of considerations come into play when deciding what version of PDF/A to use, but to some degree any version is fine. If you only have software that will produce a PDF/A-1b and that supports all the features you need, then that is a good choice, and a permanent one. Remember, given the extensibility of the PDF/A series, the first version of PDF/A is compliant with all later versions, and there is never a reason to convert a PDF/A to a more recent version of the PDF/A format.

There are a couple of basic rules you can follow in making your choices. The first is that the best conformance level to use is always level a, which will always produce the most accessible file. Barring that, you should choose level u, for its Unicode encoding, but keep in mind that the basic level (b) will almost always be sufficient for your needs. It also makes sense to use the latest version of the series that you can produce, because doing so will allow you to support the greatest number of features.

What might be a more important consideration is your color encoding. If you will need to print out high-quality copies of a document, then you should choose CMYK encoding (which stands for Cyan, Magenta, Yellow, and Black). But if you expect only to be reading your files on a computer screen then RGB Color (for Red, Green, and Blue) is your better choice.

To create a PDF/A, you need a product that can produce PDF/As. One of the most commonly used products is Adobe Acrobat Professional, versions 8 and later. Keep in mind, however, that there are many other software products you can use as well, and some of them have different features that you might find useful. (For a list of some of these products, see “Appendix A: PDF/A Tools.”) Also, a number of general products, such as the Microsoft Office suite now include tools within them that create PDF/As, so you may not need to purchase any new software at all, depending on your needs. If you need to create many PDF/As all at once, though, you’ll need to purchase a product focused on the creation of PDF/As, because those support batch processing, which allows you to convert multiple documents at once.

Conversion Practices

The process of converting a digital file into a preservation file is technically called normalization. In this process, the target format (in this case, the PDF/A) has to be one that meets the requirements of a preservation format, so it has to be a format that is not expected to disappear or become unusable in the near future.

What you need to ensure before converting any files is that you have the necessary fonts installed on the computer you are using for the normalization. Without the necessary fonts, you will not be able to create a PDF/A. Of course, this is not an issue when converting a scanned image into a PDF/A.

When to create a PDF/A

You actually have a choice of when to create a PDF/A, and you may choose to create PDF/As at different points in a records life cycle based on your business processes for different records.

At the point of creation
Sometimes, you can create a PDF/A as the original document, thus sidestepping the issue of conversion altogether. Doing so allows you to begin the life of a document in a format you know will last. If you do this, you will have to do it only with documents that you will not have to modify over time. Usually, PDF/As are made at creation only as output from large databases.

At the point of recordation
Recordation is the process of making a document a record. For instance, you may create multiple versions of a report, but only the final version will be the record. So when you have completed the writing and editing of that report, you can save the file as a PDF/A, which freezes the file, making it more difficult to modify. The other advantage of this technique is that it allows you to distinguish easily between interim drafts and the final version, because the PDF/A will always be the final.

At the point of archiving
Most people still convert documents, paper and electronic, to PDF/As at the point of archiving, at that point that they decide to store the record as an archival record by creating a preservation copy of it.

Scanning from paper

When scanning from paper, you have to set your scanner to create a PDF/A-compliant file. You then scan the document, keeping all pages of the document in one PDF/A, and run OCR text recognition, if needed, to convert the text within the document into intelligent digital text.

Converting existing scanned images

If you have existing digital images of text documents to convert to PDF/A, you can use PDF software to conduct OCR text recognition and save the file in your chosen version of PDF/A. Only conformance levels b and u are possible when scanning records, and level u is preferred.

Using the Distiller engine

One method of converting a file to a PDF/A is available only in Adobe Acrobat, and that is the Distiller engine. Distiller works separately from Adobe Acrobat, but it is also part of that software. It is usually accessible on the taskbar of your computer. To create a PDF/A with the Distiller, you would choose the appropriate PDF setting and then save or export the file. The Distiller engine may be a little more convenient sometimes, but it has no other advantages, and it cannot produce a fully accessible file (meaning one that meets conformance level a).

Converting from within proprietary software products

You can also create a PDF/A from within many software products that do much more than create PDFs. These include word-processing, spreadsheet, and page layout software. You can usually create PDF/As by “printing” or saving files to PDF/A, but you must be sure to change the PDF settings to your PDF/A preference. You can also set the software’s default to your preferred settings, for ease of use later on.

Converting from regular PDFs

Many people have stores of regular PDFs that they want to convert to PDF/As for preservation purposes. To do this, you might first have to remove any features that are prohibited in PDF/A, or you can run the conversion and see if any errors occur during the conversion. If using Adobe Acrobat, you will have to use its Preflight function to convert a regular PDF to a PDF/A. Since PDF-to-PDF/A conversions are notoriously unsuccessful, you might want to purchase a product designed for such conversions. The product 3-Heights PDF to PDF/A analyzes files in more detail to afford you a higher success rate in conversion. Still, no product will always be able to produce a PDF/A from regular PDFs.

Any form of reprographics (such as microfilming, imaging, or preservation photocopying) must include a quality control step to ensure an accurate copy of the original has been produced. The same is true of the process of normalization.

There are two basic steps to the quality control of a PDF/A. First you must visually inspect the document to ensure that the new file looks just like the old file. If the conversion has somehow gone awry, you should be able to see this in the file and then repeat your conversion processes, after rechecking your settings and methodology. The second step in quality control is to validate the created files’ conformance to the version of the PDF/A standard you are using. To do this, you’ll have to use any of a number of validation tools, including Adobe Acrobat’s Preflight function. For a list of such products, see “Appendix B: PDF/A Validation Tools.”

The preservation of records involves much more than simply creating PDF/As. It requires much work over time, and constant vigilance. You must develop solid conversion procedures, followed by good quality control practices. You will have to create and maintain metadata on the files to make them accessible and usable. You will need to ensure that your environmental controls are good for the storage of electronic files and that your data management controls (especially backup procedures) are sensible and consistent. And you’ll have to ensure one other fact: that your chosen file format for storage remains a valid preservation format. Right now, PDF/A is a good format for the long-term storage of documents, particularly digital textual documents, but that might not be the case ten years from now.

Adobe Acrobat





PDF Tools AG


Adobe Acrobat Preflight Function

Callas Software’s pdfaPilot

PDF Tools AG's 3-Heights’ PDF Validator

Appendix C: Additional Resources

PDF/A Standard

Extensible Metadata Protocol

General PDF Resources


Email recmgmt@pachasnack.com

Issued 8/08/

Источник: [pachasnack.com]
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Formats - PDF

The Portable Document Format (PDF) has become a commonly used file format for representing electronic documents independent of the operating system, hardware, or software used to create them. This format was created by Adobe and was released as an open standard in

An additional file format PDF/A was developed specifically for long-term archiving of electronic documents. Adobe Acrobat reader can still be used to view these files. This format is a subset of PDF, because it is just a PDF file that leaves out features not suited for long-term archiving. As a result, PDF/A documents are % contained. This also means that PDF/A documents are typically larger than their PDF counterparts because more information needs to be embedded in the document.

Get the latest version of Adobe Acrobat Reader to interpret these PDF or PDF/A files.


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pdf file reader Archives

Talk:PDF/Archive 3

This is an archive of past discussions. Do not edit the contents of this page. If you wish to start a new discussion or revive an old one, please do so on the current talk page.

Why called PDF?

Where does the name come frome? Aren't all files "portable"? I can e-mail .doc and .ofm just as well. Just wondering why pdf.

i think the first sentence now addresses this, perhaps somewhat (points 1, 2 & 3): PDF is used for representing two-dimensional documents in a (1) device-independent and (2) display resolution-independent (3) fixed-layout document format. That is to say, you can email any doc, but they'll appear quite different unless they're PDF or PS, hence, not "portable", i suppose. Michael (talk|contrib) , 23 July (UTC)
Portable means also platform independence, i.e. PDF can be generated, processed, and rendered on many platforms. --AFBorchert , 3 December (UTC)
also can contain embedded resources, unlike HTML that links to external files (talk) , 10 June (UTC)

I Disagree

I don't know how this became an ISO standard. Is this a new way to market software, by making an ISO standard for it's format? There are several statements in this article that are simply not true. PDF is not an open standard. It is a proprietary format. It is not software independent. PDF is not even a good format. It is unlikely it will become the defacto standard for web documents as the article implies. The whole point of web documents is to separate content from presentation (e.g., HTML, XML). I assume this article was written by someone in Adobe and is clearly marketing fluff. Mingramh (talk) , 7 May (UTC)

I believe that Lee Harvey Oswald acted alone, I believe there oughta be a constitutional amendment outlawing Astroturf and the designated hitter. —Preceding unsigned comment added by (talk) , 8 May (UTC)

"Further criticism"

I was tempted to remove the following paragraph, but there may be something in there, which I do not understand:

"Further criticism is also centered around the restrictive, proprietary nature of the format, which does not allow free, direct encoding and modification of documents in PDF."

What does "free" mean here? Surely with a text editor, you can go in and modify any PDF file, as much as you want. You cannot usually add a paragraph to a text, and I think it is valid to mention that restriction, but that has nothing to do with the fact that the format is proprietary.

What does "direct encoding" mean? Are we talking about encryption or character set? If it is encryption, it seems the "criticism" simply is that the encryption algorithm is not free. But then, no one "criticises" Word for not being free, do they? I do not see any problem with the character set in later PDF formats, even though it could be messy in earlier version. Mlewan , 9 January (UTC)

This seems, to be honest, to be nonsense. If the comment is that PDF files are hard to directly edit and create (without using software), because of the complexity of the design of PDF, this is true (relative to simpler formats), but is unconnected to the proprietary origins. If this is stating that it is difficult because it is proprietary, this makes no sense: the PDF specification is readily available. If it is saying that because it is proprietary, free/open source software is not allowed, this is just wrong. So I have removed it. Of course, if I've completely misunderstood a valid and verifiable criticism, it only needs to be added back with a suitable source. Notinasnaid , 9 January (UTC)
Is it really relevant whether the criticism is valid? All that would be needed is a reliable source showing that this is a common criticism. Those who think it's a bad criticism (and I include myself) could cite sources refuting it. I agree with the deletion but I think it's an unnecessary distraction to argue about whether the criticism is correct; WP:NOR is a sufficient reason to delete it. Mrhsj , 9 January (UTC)
Quite right. Verifiable is enough; I should not have said "valid". However, it does need to be comprehensible. Notinasnaid , 9 January (UTC)

There are two potentially valid points that might be made. It is possible that the basic internal file format of pdf is such that it is difficult to modify/edit the contents. And it is very likely that part of the current wave of security features of all sorts is to intentionally make it extremely hard to edit/modify the contents of pdf files that use such security features , 12 February (UTC)

Reverse engineering a pdf

Something about how to reverse engineer a pdf back to the point where it was saved as a pdf would be useful on this page. People are always asking me if they can do this; as i have only a hazy idea that there are tools out there that can do it I usually sidestep the question. Daveches , 24 January (UTC)

That isn't relevant to the article, which just describes the file format. There are plenty of tools which can work directly with PDF files. Chris Cunningham , 24 January (UTC)
The buzzword you want is "extraction": you're just getting out content, not reverse engineering which means something quite different. Notinasnaid , 24 January (UTC)
The buzzword is not necessarily "extraction": it's often about fomatting as well as content. eg if I have Microsoft Word on my machine and the PDF was saved from Word, can I get back to the Word document with all its formatting (eg to make a change then resave as PDF?)Daveches , 26 February (UTC)
There are commercial tools that will attempt to convert a PDF to Word format. They generally do not do a perfect job. The fact that the PDF format typically does not preserve all the information required to represent its source word processing document is germane to the article and it would be reasonable to include a statement about this if someone want to take the time to write a good well-sourced one. But a discussion of the capabilities of particular tools would be off-topic - this isn't a tech support forum. Mrhsj , 27 February (UTC)

Backwards Compatibility

The sentence about backwards compatibility should probably be deleted or changed. 1) No Backwards_Compatibility means newer readers can't read (some) older files, not the other way around - what the article currently claims. 2) Backwards Compatibility is almost always a function of the particular reader software used, not the format itself. Because this article is about the format, the statement is very confusing. I've also found no reference to backward compatibility issues online, and I'm inclined to think that the original author of that sentence was just frustrated because old reader software doesn't open new PDF documents; but that isn't really a backwards compatibility issue. Dana Powers , 1 March (UTC)

The sentence originally read "forwards-compatible." I wrote that, and that's what I meant. Someone changed it to backwards-compatible, which is incorrect. To me, saying "the format is backwards compatible" means that a reader written to a new specification will be able to open files written to an older specification. To say "the format is forwards compatible" means that a reader written to an older specification will be able to read a file written to a newer specification. The PDF format is backwards compatible; it is not forwards compatible. Mrhsj , 1 March (UTC)
Ahhh - which makes way more sense. It should definitely be changed back to forwards compatible then. Right now its just a logically confusing sentence. A cite would also be nice, as would clarifying that this is a property of the specification itself, not just a single application. Dana Powers , 1 March (UTC)
I do not get the point. Is any format ever forwards-compatible? Not even common text documents of today can always be opened in old versions of vi, because text files now often are UTF Check out .doc, .xls, , .rtf, .psd, .tif Is any of them or any other format forwards-compatible? Mlewan , 1 March (UTC)
It is extremely difficult to achieve forward-compatibility, to be sure, which explains why most of the document formats you mention are not forwards-compatible. But it isn't impossible. Dana Powers , 1 March (UTC)
I've investigated a little further and found the BX and EX operators (this in the spec; I haven't looked at others). They allow a PDF writer to specify that certain commands in a particular document should be ignored when read if they are unrecognized. This would allow creation of forwards-compatible PDFs, but it doesn't require it. Dana Powers , 1 March (UTC)
Yes. There are features in PDF that were intended to facilitate forwards-compatibility. That's why I rewrote the statement that said the format "wasn't designed" for forwards compatibility - it kind of was, it just didn't fully achieve the goal. I don't have a copy of the spec so I can't do a proper sourced statement, but I recall that it promised that if a non-compatible change were ever introduced to PDF (one that would break an old reader completely) then the PDF version number would be bumped to But such changes were in fact made (e.g. with the introduction of Flate in and Object Streams in ) without the major version being bumped. Mrhsj , 2 March (UTC)

Openness and old Microsoft rumors.

I deleted this material: "(There is now some contention whether PDF will truly be an open standard in light of Adobe Systems threatening to sue Microsoft Corporation for including the ability to write PDF's in some of their products, see external links.)"

Here's the history: in June Microsoft decided to change its PDF export tool from a bundled add-in to an add-in users would have to go their website to download. They claimed this had something to do with a threat of a lawsuit from Adobe, but this was never confirmed and no suit was filed. Then in January Adobe announced it was going to submit PDF to a standards body.

I don't see how those facts support the claim that "there is 'now' some contention". That statement would require citations showing that there has been controversy *since* the Jan announcement, and that that controversy had something to do with this old rumor. Mrhsj , 15 March (UTC)

Agreed. The reported existence (or threat) of this antitrust suit has been widely used to support all manner of tenuous conclusions, in this article and elsewhere. Notinasnaid , 15 March (UTC)
It may be worth noting a particular error: some people assume that because Adobe is reported to be considering a suit because Microsoft may add PDF creation to Office, that therefore it must be because PDF is a secret, or requires a payment or license to develop for, and Microsoft don't have Adobe's permission for this. To be clear, no permission is needed, PDF is not a secret, and these are not the grounds for the reported threat of a law suit. Notinasnaid , 15 March (UTC)
I suggest the you STOP removing any discussion of the openness of PDF until you can point to ONE article from ANY source where a representative of Adobe states that they have no intent to sue Microsoft (or any one else) for inclusion of PDF code in Office (or any other product). This smacks to me of someone who has a strong vested interest in Adobe and is not interested in unbiased reporting of the facts. It should also be noted that handing a specification over to a standards body does not in itself make the standard open in any real sense. Please review the situation with the JPEG standard which was built from the ground up as an open standard, but was the subject of extensive litigation years later. Forgent Networks sued over 30 corporations for patent infringement for creating applications that could read and write in the JPEG "standard".
So, come forward with VERIFIABLE proof of your claims that PDF is an open standard with no threat of litigation, or stop removing discussion of this issue. It is critical information to anyone that is considering adding PDF support to an application they may write. Your whitewashing of the issue does not help. - Sincerely, a non-Adobe employee. —Preceding unsigned comment added by (talk) , 20 March
I believe you are mistaken. The burden is not on editors to show that that Adobe have denied an intention to bring a suit against Microsoft. The burden falls on an editor who wants to add information that it is verifiable. The suit has been reported, but drawing conclusions about the openness of the standard from the suit seems to be entirely different, and this requires a reliable source. Reports I have read sugest the suit relates to anti-trust issues, not intellectual property or standards. You also seem to be confusing open standards with patent issues; these are entirely different things. Some open standards contain acknowledged patents and some are alleged later. However, there is disagreement on the definition of "Open standard", please see the article for details. If you are interested in Adobe's statement on the intellectual property issues connected with PDF, please see section of the PDF Reference. Notinasnaid , 20 March (UTC)
I still disagree, my points are very well documented. There are at least 10 articles from reliable sources that discuss the pending lawsuit, but NONE that state there is no threat of lawsuit. How can you continue to state that the "burden falls on an editor who wants to add information that is verifiable". My information is completely verifiable, yours is not. Also you state that "suit relates to anti-trust issues, not intellectual property or standards". Well, it doesn't matter what the suit relates to directly. It directly influences the format and is critical information that someone who comes to Wikipedia might need to know (e.g. if they are deciding if they can add PDF export to their product). If you still disagree I suggest an independent third party review what is verifiable and decide if this information should be shown in the wiki entry. So far I see little to convince me that you aren't just an employee of Adobe who has a strong vested interest in showing that company in a positive light. I don't work for Adobe, Microsoft, or any other company that has a vested interest in the PDF/Markup business. However I strongly suspect that you do. —Preceding unsigned comment added by (talk) , 20 March
Please try to rein in the personal attacks and let's focus on the article content. If this article reports the lawsuit it can only report what the reliable sources say. If the source draws conclusions, it can report those conclusions (as quotes, if they are not universally agreed). But if editors draw those conclusions, this is original research and clearly not allowed. My view is that what people planning to add PDF export need to know is in the PDF Reference, as defined above, do you have a reliable source that contradicts this Adobe source? Now, I'm going to wait and see what others say. Notinasnaid , 21 March (UTC)
I'm not making a personal attack, but I am questioning whether you are impartial. I think it is quite well established that impartiality is critical when providing public information. I believe you should state unequivocally whether you are financially compensated by Adobe so other readers can fairly judge your motivations. This becomes a critical issue over time since someone who is paid can keep arguing forever, whereas someone who wishes to add content because they believe it to be accurate and in the best public interest to distribute will eventually give up. Whatever the case, I hope a disinterested third party will make a judgement so I can move on. If they say I'm wrong and the information should not be present, I'll drop it immediately, but if they say the content should be present I think it should be added and you should be prevented from removing it. —Preceding unsigned comment added by (talk) , 21 March
Well it's been a couple days and no third party has given an opinion. Unless someone offers an opinion soon, I'm going to add content discussing the lawsuit back in since it appears to be a simple difference of opinion and there is no consensus. Unless someone else rules, I expect that the content will be left in the article. Twikir , 22 March (UTC)
The rationale for removing it is still valid. This isn't a case of consensus, it's a case of policy, which says that random unsourced or poorly-sourced contentious material has no place on Wikipedia. (out of interest, are you the same user as the anon above?) Chris Cunningham , 22 March (UTC)
As I see it, the contention is whether the threat of suit by Adobe over Microsoft's attempt to add PDF creation functionality calls into question the concept of PDF as an 'open standard'. Do we have a reference that actually makes the above supposition? If so, put it in the article with the citation of the source and let's be done. If not, then the supposition is original research and it shouldn't go in. Whether Adobe actually has any intent to actual start litigation seems irrelevant to the issue at hand. Blade , 22 March (UTC)
I agree we shouldn't link the two. However I do think the lawsuit is relevant to PDF as a format and it should be mentioned in the article somewhere. Personally I would say it strange for Adobe not to deny the lawsuit if there was indeed no threat. While obviously we can't mentioned this in the article, it seems to me therefore likely that there was a threat. Most likely the threatened law suit was not copyright/patent (as even before Adobe annouced they were going to submit PDF to the ISO, you could still use it provided certain conditions are met) related but anti-competitive behaviour related , 20 April (UTC)

I'm not sure if the question was directed at me, but since I'm the one who removed the material in question, I'm happy to state that I do NOT have a conflict of interest on this topic as defined by Wikipedia. Mrhsj , 22 March (UTC)

The section Technical Foundations states that Adobe licences on royalty-free bases the patents on pdf. But the webpage to which this is referenced actually does not list any patent for which that is true. quote: Accordingly, the following patents are licensed on a royalty-free, nonexclusive basis for the term of each patent and for the sole purpose of developing software that produces, consumes, and interprets PDF files that are compliant with the Specification: U.S. Patent Numbers: But no patent number is listed. So it looks like that claim applies to no patent. If no one has a better reference I'd suggest to modify the text. Poderi (talk) , 3 March (UTC)

Haha! Looks like a problem with the styles on the Adobe web page. Actually the patent numbers ARE listed, but they're displayed in the background color, so they're invisible. If you select the text in that area and copy/paste to a text editor, you can see the patent numbers. Adobe just needs to fix their HTML. Mrhsj (talk) , 3 March (UTC)

Comparison of layout engines (XHTML) see also link

Is the "Comparison of layout engines (XHTML)" link under see also really relevant for this article, or am I missing something? --ScottyWZ , 17 March (UTC)

biast in the article

my question is why does this article have an advantages section and not a disadvantages section to me this is an obvious biast towards adobe. —The preceding unsigned comment was added by Dr noire (talk • contribs) , 13 April (UTC).

Well, add a section on it then. Just be sure that you cite your sources and the sources are verifiable. Avoid original research as well. Blade , 14 April (UTC)
It's a bit silly to call that a bias toward Adobe, since PostScript also came from Adobe, and PDF is their successor format. Kenahoo (talk) , 15 July (UTC)

Copyright violation?

The "Advantages" section seems like it has been picked up from PDF/A - Your Advantages, which is also acknowledged in the revision where it was added. It seems like a clear case of WP:COP to me, removing the content for now -- AshishKulkarni , 3 May (UTC)

HTML phoning home

"Like HTML files, PDF files may submit information to a web server." Can HTML files phone home? Sure, javascript embedded in HTML can, but HTML can't (AFAIK) --Taejo|대조 , 13 May (UTC)

Well, in PDF's case it's also "JavaScript embedded in PDF" that actually phones home. So the parallel is pretty good. Mrhsj , 13 May (UTC)
Web bug (talk) , 10 June (UTC)

Some re-work to the organization of the content

I suggest that instead of "Technology" use "Format overview" and have the following sub categories (that follows the topics in the PDF reference ):

  1. Imaging model
  2. Portability
  3. Compression
  4. Font management
  5. File generation
  6. Random access
  7. Security
  8. Incremental update
  9. Extensibility

With this, the article (at least the tech part) will be firly complete and describe the interior of the format. Any objections? Khecaji , 6 July (UTC)

Be bold. Go for it. Chris Cunningham , 6 July (UTC)

New wikiproject

Is there any interest in starting a wikiproject dealing with various representations av information (e.g. imaging models, presentation layer, content layer) and related methods for cross-referencing (e.g. integration of related information that exists in various digital as well as printed formats)? Dynamics of information and related problems.

PDF Catalog: part of PDF, application-specific extensions?

The PDF "Catalog" (search index) -- is this part of any type of PDF-related standard (eg, open specification?) or completely a proprietary closed-specification add-on to Acrobat? Can any PDF reader (eg, see "implementations") use the ".pdx" index file, and could any application generate the index (catalog) file? Michael (talk|contrib) , 23 July (UTC)

Icon Image

Perhaps some information on the traditional PDF icon images would be handy - especially the one used on Wikipedia when linking to a pdf file (it should be noted that finding the URL for this image seems all but impossible) - and perhaps even tell where one can actually access a public domain variant of this icon. I understand if that's too specified of a topic for this, but I'm sure there are people who could use it (including me). Shoreu , 27 July (UTC)

pdf (probability density function)

, 31 July (UTC) Pdf is also a common abbreviation for Probability density function


Shouldn't this also be on the wiki of pdf?

It is on the Wiki. You have a link to it just there. To find it from the abbreviation you go through PDF_(disambiguation), which is linked to from the top of Portable Document Format. Mlewan , 31 July (UTC)

Editing PDF files

Could someone provide at least one example for this: There is also specialized software for editing PDF files.Palpalpalpal , 12 August (UTC)

Acrobat Professional. Nitro PDF. Foxit PDF Editor. Iceni InFix PDF Editor. Enfocus Pitstop. Jaws PDF Editor. Mrhsj , 12 August (UTC).

iText is an Open Source library for creating and manipulating PDF, RTF, and HTML files in Java. , 19 September (UTC)


The article needs a great deal of additional material describing PDF file internal structure. Until then, reading a page reference manual is not an inviting place to start. Here are some options:

, 3 October (UTC)

Your wish is my command. Just added some stuff; see if you like it. Mrhsj , 5 October (UTC)


I think the sentence "An up-to-date antivirus program is paramount" does not have to be in this article. —Preceding unsigned comment added by (talk) , 11 October (UTC)

Indic Support

I have issues with Indic Languages (including my mother tongue Tamil). I can covert a UNICODE word or any document to a pdf however when try to copy and paste back to Microsoft Word doesn't work. I tried various tools like doPDF, Acrobat but I don't have a solution. Is there any work around avaiable? or does it support most of the European languages only? please clarify. --Umapathy (உமாபதி) , 11 October (UTC)

CMYK jpgs

The image streams embedded in pdfs are sometimes jpgs (/DCTDecode) that can be extracted by hand into a file and viewed. But they are not always RGB; they may be /DeviceCMYK -- 4 bytes per pixel instead of 3? Which image viewers can properly handle CMYK jpgs? Irfanview sort-of recognizes the file type but shows false color, and then saves as a wrong RGB. Image Analyzer says it can handle CMYK, but does not seem to do it by default -- maybe with the ImageFileLib plugin? , 19 October (UTC)

i am writing to ask about how do you send the PDF files to the internet and can you send me some files on dida ict courework and some other files thank you —Preceding unsigned comment added by (talk) , 5 November (UTC)

This 10 mo. User Barnaca is CENSORING My contribution

Ok so this user pachasnack.com:Barneca

is removing my table which outlines pdf conversion options (their pros and cons by price and user-friendliness and comments etc.) I didnt read my messages and resposted it because my table was removed the moment I put it on.

So I want to know what PDF conversion options are there , right. How do I find out&#;? I start a table on wikipedia listing the pdf converstion options. Since I only know two tools Acrobat Professional and cutePDF (which is two more than 99% of the world) I posted those two on the page. Now Mr. Barneca thinks I am spamming for Cutepdf. The software is free! my professor recommended it for our class but I didnt find it entirely useful because evne though its easy to use the darn thing only converts one way -> all formats to PDF. I also tried Acrobat Professional conversion option but that didnt work so well so I posted my observation. Now for heaven's sakes is this clear that I am not a spammer? Could you please stop being the censor here and permit me to put some foundation for finding out the converstion options I have?

If you dont want me to a put a table or something with applications working with PDF standards how else would you want me to frame this? How would you suggest I start a framework which others could fill with information regarding PDF converstion options? Is not a table listing the applications, their cost, their usability and their TO FROM conversion fields appropriate in this scenario? This is really absurd. —Preceding unsigned comment added by (talk) , 7 November (UTC)

I see two issues:
  1. Whether you are "spamming" or not. It looked like it to me. I might be wrong. I'll assume the best, that you aren't, and apologize for jumping to conclusions and not assuming the best earlier.
  2. Whether this information belongs in the article or not. I think it does not. Wikipedia isn't a buying guide, and I don't think comparison tables about products belong in an encyclopedia article. You may not be spamming, but if we leave this table in, I guarantee it will be a spam magnet, and will soon be loaded with links to every PDF-related product imaginable. This is not "censoring" you, it's saying I don't think it should be here. If a consensus forms on this page to include such a comparison table, I'll gladly yield to consensus. It currently is unsourced as well, but I'll assume if consensus forms to include it, we can find references for everything.
I look forward to hearing other views. --barneca (talk) , 7 November (UTC)
My opinion is it was right to remove the table. First, a table of this sort does not belong here. Please see WP:NOT, especially the sections on "Advertising," "Directories," and "Sales Catalogs," and "Instruction Manuals." The topic of this article is "Portable Document Format," not "tools for creating files in the Portable Document Format." Second, even if it were right to include the table, the content was unacceptable because the content violated WP:NPOV, for example by calling one product's quality "Poor".
Both of you, please assume good faith. User Barneca has already apologized for calling the table "spam". Anonymous user, it is not appropriate to accuse user Barneca of "censorship." It was simply an edit. Wikipedia editors routinely remove content they believe violates site guidelines. Assume good faith and debate the merits of the content based on Wikipedia policy. Mrhsj , 7 November (UTC)

Deleted Microsoft section.

I deleted the section headed "Competing PDF Standards," which had the body, " Microsoft announced its competing PDF standard based on XML Parser Specification in In response PDF announced its own Mars project a year later following a breakdown in talks between the two companies over co-operation."

Reasons: First, the heading and beginning of section are nonsensical. XML Paper specification is not a "PDF Standard". What is a "PDF Standard" anyway? Second, "PDF announced" is nonsense. PDF is a file format, and it doesn't know how to talk. Third, Mars is already discussed elsewhere in the article. Fourth, whether Mars was a "response" to XPS or not is a matter of conjecture, as is the question of whether it had anything to do with a "breakdown in talks" (between what two companies? Is PDF a company?). Such speculation needs to be identified as such an attributed to reputable sources.

I don't think the section added enough value to the article to be worth trying to salvage. Mrhsj , 7 November (UTC)

PDF Ebooks

I'd really like to get an ebook reader to alleviate eye fatigue and portability. The Sony Reader has poor support (in terms of the average pdf you might get from a website) and the new Amazon Kindle is much worse. Since most of my ebooks are pdfs, I thought I'd ask here why is it so difficult for portable devices to support the portable document format? Is there any reader that has good if not great support for pdfs? (talk) , 7 December (UTC)

The reader that currently has the best support is the iLiad, but it's fairly expensive (up from €/$ (yes, the EU/US price difference is fairly startling due to current exchange rates), which uses iPDF as a viewer, with different extra features available (bookmarking &c.), along with a Wacom system for making annotations/notes/whatever in them. (I've got one) Boombaard (talk) , 28 June (UTC)

copy protection using custom embedded fonts

Apparently, a new approach to protecting PDF content is to use software that generates "random" text, but also includes custom embedded fonts to make the document read and print correctly.

This makes it impossible to copy the text (search the document etc) as it will come across as random garbage when not viewed in the custom font(s) specifically created for that particular document, all without having to protect or restrict the PDF in anyway (protections that can be cracked anyway).

Now, as far as I can see this isn't mentioned at all on Wikipedia. Which programs have this feature? How well does it work? etc etc Any discussion or links much appreciated.

(talk) , 21 January (UTC)

What is your source? Or an example of an obfuscated PDF? If it's just letter replacement it should be easy to decode. —Preceding unsigned comment added by (talk) , 6 November (UTC)
What you are seeing is the use of subsetted fonts without providing a ToUnicode mapping to facilitate text extraction. As the PDF security features already allow text copying to be disabled I think it is more likely that what you are seeing is a buggy PDF writer that fails to embed the mapping from the font glyphs back to Unicode as recommended by the PDF specification. —Preceding unsigned comment added by (talk) , 15 November (UTC)
"As the PDF security features already allow text copying to be disabled" -- the pdf security options are pretty thoughroughly broken though Plugwash (talk) , 2 May (UTC)

Creating PDFs

I think a section on how PDFs are created would be useful, I'd add one myself but I don't know how to create a pachasnack.comge (talk) , 9 February (UTC)

PDF editors and software printers are mentioned in the article, see also List of PDF software—Preceding unsigned comment added by (talk) , 6 November (UTC)

Viewers, editors, and tools

The above quoted page contains external links (pachasnack.com#External_links) among them the sub-section "Viewers, editors, and tools".

I am trying to add the URL (pachasnack.com) to our own website to that list.

I think that the URL has value to people and there are absolutely no strings attached. The website is free, there is no registration, nothing. It provides an online conversion capability so no software installation is necessary to create PDF files from proprietary content. People use the service after seeing the link in the Wiki Document and seem happy.

But the link is constantly deleted, being defined as "Spam" as "Shareware", etc. I seriously doubt any of the editors deleting the link have even so much as looked at the page it refers to. The section and subsection show links to e.g. Adobe (commercial software), Docudesk (dito) and many more. Our conversion page offers a place to convert a single document without having to buy anything, without the need to install software. A service to the community. No more, no less and I thus think that it is a valuable addition to a document such as this one.

Comments would be very welcome!

Ph wiki edit (talk) , 8 April (UTC)

I'd rather remove existing links to tools such as dwg2pdf or to tutorials such as "Use Photoshop to create PDF Documents". There is a separate page for List of PDF software. Engelec (talk) , 2 February (UTC)


Would it not be fair to add a criticism section, ie: takes ages to download on slower connections, causes computers to crash when they are opened without saving? (talk) , 29 June (UTC)

Certainly, if you can find reliable, current sources that make these criticisms about the file format itself, that would be appropriate. The examples you give are somewhat suspect though: all large files are slow to download on slow connections regardless of what format they're in. And I would be surprised if you can find evidence that the file format itself "causes computers to crash"; that sounds more like a tech support issue with some particular application, which would be well outside the scope of this article. Mrhsj (talk) , 29 June (UTC)
I think it would be quite valid to add a criticism section, even if it isn't specific file type. I believe many criticisms for PDF files would stem from two things, mainly the de-facto viewer acrobat reader/adobe reader and users using the PDF file type over better alternatives. I believe it is fair to criticize PDF due to the shortcomings of Adobe Reader because not only is it the de-facto viewer, it is also made by the same company who developed and maintains the PDF standard. Additionally, nearly every form of media that links to a PDF, be it a website or CDROM either includes a copy of Adobe Reader or links to Adobe's Adobe reader download page. Also, Adobe Acrobat and Adobe Distiller are the de-facto methods for creating PDFs and they themselves are subject to harsh criticism. Because of the strong coupling of PDF and Adobe Reader, Acrobat, and Distiller, any criticism aimed at these products can, IMO, be safely aimed at PDF as well. PDF is marketed extensively and almost exclusively by Adobe. Adobes marketing has lead to users making poorly informed choices of their export format. Criticisms of the DOC format stemming from deficiencies in Microsoft Word would be pretty similar in nature, and, i beleive, valid as well. At the very least a section on the incorrect usage of PDF over say asci text, HTML, or jpg/png would definitly be valid, along with a link to criticisms of Adobe Reader. —Preceding unsigned comment added by (talk) , 27 January (UTC)
This Article smells like it was written and edited by Adobe. Can someone find out if this is the case? (talk) , 28 January (UTC)
The DOC format isn't an ISO standard, afaik. PDF is also widely used with LaTeX, both for output and for embedded graphics, and for good reasons, without any need for Adobe software. On Mac OS X, PDF is a native format with good support in Cocoa, the viewer provided by Apple isn't Acrobat Reader, and creaing PDF files is as easy and as native as printing. Engelec (talk) , 28 January (UTC)
I would like to express my support for a "criticism" section based on the format and it's practical uses. A page(biased and old, I must admit, but still true) that explains some of the disadvantages is found at: pachasnack.com (talk) , 27 February (UTC)
I would like to see a Criticism section on this article, too. Even as recently as March , I am hearing complaints of PDF not being open enough to export data reliably, with third party programs. Since PDF is a pillar of modern document formats, this is an important question - whether PDF formats are open enough. This article cheers Adobe's efforts to create PDF as an open standard, but it offers no insight into the other side of the argument. It is not hard to search for articles that take this position (am reading InternetNews article called "Adobe: Open but not Always Open Source" at the moment), so I personally would appreciate someone with some knowledge on the subject to include their thoughts on the subject here. (talk) , 14 March (UTC)
The thing about pdf (which can be either good or bad depending on how you look at it) is it is basically a metafile format. While text remains as text each line of text is a seperate object. A table is a load of lines with text objects in the grid formed by those lines. This is great if your goal is to preserve the exact layout of a document, it is not so good if your goal is to have a format you can easilly copy information out of.
Also there seem to be few good tools for getting anything more than text and bitmaps out of a pdf. Inkscape is looking promising though (debians version can already import pdf with high success rates afaict). Plugwash (talk) , 2 May (UTC)

ISO standard

Wow, PDF is so ubiquitous within the publishing circles that I kept thinking it was an international standard. I guess I was wrong. --Voidvector (talk) , 3 July (UTC)

nh —Preceding unsigned comment added by (talk) , 6 August (UTC)

No you weren't. PDF is an ISO standard. Engelec (talk) , 2 February (UTC)

Naming conventions for image file formats

Please see the discussion at Talk:Image file formats#Naming_conventions_for_image_file_formats on naming conventions for articles on image file formats. Dcoetzee , 25 October (UTC)

article is too web-centric

This article on PDF is very web-centric with the emphasis on downloading and viewing PDF files. I was involved in computer assisted typesetting at Kingsport Press from to ; I know that was an aeon ago in web-time, but we did PostScript and PDF from on.

PDF was a compressed, cross-platform compatible file format viewable on Mac, PC (Windows) and Unix, which was a big selling point. It was based on PostScript, which means that any typesetting device that supports PostScript should be able to print a PDF document. Before PostScript, every typesetting device used (VideoComp (Hell Digiset), Linotron , etc.) had its own incompatible device language. PostScript became a universal typesetter language and PDF became the universal typesetter file format.

PostScript (.PS) language and Portable Document Format (.PDF) file format established universal standards in a chaos of incompatible typesetting languages and file formats, changing type composition as we knew and practiced it. That is a very important aspect of both PS and PDF. Naaman Brown (talk) , 25 January (UTC)

Reference link failure

Current reference footnote #4 - History of pdf openness is - Page not found. Did a search of pachasnack.com to find a possible relocation. Found a top level page, but the content is indeed missing. Reference should probably be removed unless someone can find where this document has moved to.

GrandpaDave (talk) , 4 March (UTC)

Also searched the Wayback Machine for the missing document referenced at [1]. Document also not found there. Referenced material is essentially a history of releases. Will check for additional feedback and remove reference unless an alternate is found. GrandpaDave (talk) , 7 March (UTC)

"PDF format"

At three points in the article, it says "PDF format". Should this be removed? After all that means "Portable Document Format format", which is a tautology and so not proper English. Just a point. Greggers(t &#; c), 24 March (UTC)

PDF (from version ) supports true graphic transparency; PostScript does not.

That sentence isn't possibly correct -- even though I've seen it in other places. Postscript primitive operators do not support true graphics transparency; postscript itself can do anything -- it's Turing complete. A PDF interpreter can be written in postscript. —Preceding unsigned comment added by (talk) , 1 April (UTC)

The sentence is correct. The imaging model is part of the language. No amount of Turing completeness in the programming part of the language can change the fact that the PostScript imaging model is an opaque one. And no, a PDF interpreter cannot be written in PostScript, for precisely this reason. Mrhsj (talk) , 5 April (UTC)
Surely you could write code in postscript that read the pdf and combined the overlaping objects together before outputing them. Plugwash (talk) , 1 May (UTC)

Can files embed error messages?

I ran across something that piqued my curiosity. While using the PDF-XChange Viewer to read a pdf file, an error message popped up, with a standard message about not having the latest version of Adobe Reader. It seems strange to me that an alternative reader, like X-Change, would direct users to download the latest version of AR rather than their own software. So, basically it seems like there are several possibilities: 1)error messages can be embedded in the pdf file, 2)X-Change is being honest about their inability to render certain pdfs, or 3)The X-Change software is based on Adobe code. (talk) , 14 April (UTC)

Geospatially Enabled PDF

I suggest the addition of a section on geospatially enabled PDFs and the removal of GeoPDF page. GeoPDF is able to be created directly from ESRI's Arc and used in Adobe software. The current GeoPDF page is a TerraGo advertisement. Miglewis (talk) , 8 May (UTC)

It's pity that

the following citations are not hypertext linked pachasnack.com?hl=en&lr=&newwindow=1&q=allintitle%3A+ISO+&btnG=Search (talk) , 10 June (UTC)

Standard Type 1 Fonts

The title "Base 14 fonts" is confusing to the non-expert, as "base 14" in most other contexts refers to tetradecimal. The standard "Document management — Portable document format — Part 1: PDF " does not use this terminology, preferring instead "Standard Type 1 Fonts". I have changed this to clarify the heading. TimR (talk) , 8 September (UTC)

Okay, that works for me as long as we keep the expression "base 14 fonts" in the text as you have done. Although the expression doesn't appear in the Reference Manual, it does get , ghits - it is the common name used by everyone knowledgeable in the field. Mrhsj (talk) , 8 September (UTC)

Image Resolutions

When choosing between two different versions of the same digital photobook, one in PDF and the other as a collection of JPEG files, are there any builtin limitations to the Portable Document Format that render it inferior to its JPEG counterparts in terms of image resolution and quality?

This is supposedly related to PDF's inability to handle different image resolutions. Can someone please expand upon those hypothetical limitations? -- Ishikawa Minoru , 14 November (UTC)

There are no limitations in the ability of the PDF format to embed JPEGs. PDF stores JPEGs in exactly the same format as the original files. PDF has no "inability to handle different image resolutions". —Preceding unsigned comment added by (talk) , 24 December (UTC)
There aren't any such limitations inherent in pdf itself but the software used to create the pdf may well downscale images over a certain resoloution (usually this is configurable) to keep the filesize down. Plugwash (talk) , 26 October (UTC)

PDF = the file format? Why?

So a proprietary file format is more important that, say, probability distribution function? Geek war, ahoy! --Sigmundur (talk) , 30 October (UTC)

.pdf the only portable document format?

Is the format with the extension pdf the only portable document format? No other postscript print-ready formats out there? Wouldn't their generic name also be portable document format? (talk) , 3 December (UTC)

Obviously marketing had some influence over the choice of name. AnonMoos (talk) , 31 December (UTC)


Does anyone object to me setting up automatic archiving for this page using MizaBot? Unless otherwise agreed, I would set it to archive threads that have been inactive for 60 daysOneiros (talk) , 10 December (UTC)

Odd, the MizaBot page says, "Before requesting automatic archiving on an article's talk page or a Wikipedia forum, please establish a consensus that archiving is really needed there," but it looks like you set it up anyway. "No objection" within less than 2 days is probably not what they mean when they ask you to "establish a consensus," eh. (I myself would favour the Wikipedia guideline of 50 topics[2]). -- Mecandes (talk) , 15 December (UTC)
I observed the policy after placing the &#;&#;Archiveme&#;&#; template on a talk page. The archives already existed. Is automating them really a problem?--Oneiros (talk) , 15 December (UTC)

DRM restrictions question

Section "Usage restrictions and monitoring" states:

PDF files may also contain embedded DRM restrictions that provide further controls that limit copying, editing or printing. The restrictions on copying, editing, or printing depend on the reader software to obey them, so the security they provide is limited. Printable documents especially might be saved instead as bitmaps and subject to OCR.

Does this imply screenshots could be used to circumvent DRM restrictions of all PDF files? Regardless, wouldn't OCR from image files such as bitmap be a partial circumvention? It sounds to me like they could be used to create files that would be essentially the same as printing the PDF and scanning the printout. The basic text and image content would be freed from the DRM but some or all of the special functions or features of the PDF file would be lost in the transition; possibly with some variation of loss or retention depending on the format the OCR output was saved in. Moss&Fern (talk) , 11 December (UTC)

At least with conventional pdf protection you don't even need to go that far, there are plenty of tools out there that will strip the protection while leaving other stuff intact. Plugwash (talk) , 11 December (UTC)
This is exactly what happened with the Unicode spec: You can get PDFs with some glyphs, but they are DRMed. So someone made bitmaps of them and created a new PDF with all glyphs. OCR isn't really helpful for the complete Unicode spec.&#;:-)--Oneiros (talk) , 14 December (UTC)
The second half of the paragraph does not make sense. Printable documents especially might be saved instead as bitmaps instead of what? Instead of PDF, instead of using DRM? Either way, that's beside the point: it has already been stated that the DRM is not secure. If nobody objects I'm removing it. (talk) , 27 August (UTC)

Worldwide usage?

I was hoping the article might give me an idea about how widespread the use of PDF files is; is it available in all languages and countries, and is it as accessible on computers worldwide as it is in North America? (Clearly that is the intent if it has been made an ISO standard, but is it so in actual practice)? -- Mecandes (talk) , 15 December (UTC)

The format is independent of the software, and what languages the software is offered in. Adobe_Acrobat has a section on Internationalization and localization and list of languages is rather large. Bragr , 8 January (UTC) —Preceding unsigned comment added by Bragr (talk • contribs)

PostScript POV

The section of PostScript gives a one-sided "PDF is better". While this is certainly something Adobe wants us to believe, it is not necessarily trueand many who have experienced both prefer PostScript. I note that PostScript is human readable, can be edit in in a normal editor (if needed), is much easier for third-party products to support, that "imperative programming language" brings certain advantages, that it is immediately understood by good printers, (talk) , 8 March (UTC)

The neutrality tag is inappropriate and should be removed: "Simply being of the opinion that a page is not neutral is not sufficient to justify the addition of the tag. Tags should be added as a last resort" (WP:NPOV_dispute). Nobody had rejected or reverted any changes that would present an alternative point of view. If you want to present alternative opinions (properly sourced of course), go ahead. If you don't offer a constructive edit to address the problem you perceive within a few days, I will remove the tag. Mrhsj (talk) , 8 March (UTC)
Removed the tag as explained above. Mrhsj (talk) , 17 March (UTC)
I think you are not allowed to do that. First of all, you're referring to an essay (WP:NPOV_dispute), not a policy. Essays are guidelines only. Secondly POV-tags, and its kin, can only be removed if the issue is resolved here on the talk page, or if the issue times out by three months. It isn't/hasn't. You removed it arbitrarily without reaching consensus. Thirdly IP makes a proper talk page complaint, so it cannot be considered added hastily. In order to NPOV a text, all "better" and "has several advantages over" should be attributed to a specific usage, and preferably be sourced. In order to NPOV the PostScript section, the different usages should be highlighted. Subjectively: of course PostScript is better for this, and PDF better for that. They're just purpose specializations. The template
reads: Please do not remove this message until the dispute is resolved.Rursus dixit. (mbork3!) , 11 September (UTC)
Okay it is true that the link I cited is an essay, not an official policy. However it is the essay that the POV tag itself links to as a reference for how to deal with it. Is there an official Wikipedia policy governing removal of POV tags? Please cite. Thanks. Mrhsj (talk) , 11 September (UTC)

Dead Links

Some of the External Links are dead, including the first one on the list. Instead of deleting them, can someone provide the updated links? AmanAhuja (talk) , 22 October (UTC)

I found only two dead links, and took a stab at at updating both: [3]. Not so sure about the AIIM one; maybe someone else can do better. TJRC (talk) , 22 October (UTC)

Portable Document Format or portable document format?

Hello, I reverted one edit in the article and changed first letters of the name "Portable Document Format" to capitalised letters. According to ISO specification:

Section 4 (page 7): "4 - Terms and definitions"

  • " - PDF - Portable Document Format file format defined by this specification ISO ".

Section Introdution (page 17)

  • ISO specifies a digital form for representing documents called the Portable Document Format or usually referred to as PDF.

(talk) , 11 February (UTC)

How to read a PDF file

The article needs some discussion on how to open a PDF file so you can read it. Most public computers I use CANNOT read PDF. They call for an association that has to be down-loaded, which is, in my situation, almost never possible. The idea that PDF files are universally readable is in error (talk) , 12 April (UTC)

You may find this article instructional. Like most articles on software specs, the main article avoids talking about specific implementations, unless there is some notability (Adobe Acrobat and Reader are mentioned because they were the only official implementations when the format was proprietary). I believe the two most popular readers for Windows are Foxit Reader and Adobe Reader. --Nicholas Davidowicz (talk) , 12 April (UTC)
We have a list of PDF software but I don't see that helping you much if you can't run anything you download. You need to complain to the people in charge of those "public computers" and/or stop cheaping out and either get your own internet connection or find somewhere that actually cares about their users. PDF is a very common format and anyone offering a general purpose computer for internet access should really be offering a PDF reader. Plugwash (talk) , 12 April (UTC)

"Open standard"?

I question the description of this proprietary thing as "open standard". If this is allegedly an "open standard", why can I not access the source code of a PDF document and make changes? For example, I need to correct typographical errors in a document, but the publisher used an extremely obscure font that I'm not able to find anywhere. If the font is embedded in the document, this shouldn't be a problem if this was an "open standard", it would only be a problem for a very proprietary application that deliberately tried to prevent the document from being "open" -- and in any case, I'd be happy to use a different font to make changes such as adding a comma, I couldn't care less about the font that's already used. I'm aware that older versions of Acrobat Pro did not prevent you from editing text if you didn't have the exact same font installed. Potbirohotballa (talk) , 31 May (UTC)

Open standard does not mean any document can be opened and read by everyone. Open standard means the specifications for creating and reading documents are publicly available. --NeilNtalk to me , 31 May (UTC)

Add "PDF searchable image" concept to the article?

There are a important PDF concept in the digitalization and OCR

Источник: [pachasnack.com]

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