Question about PDF manipulation

On 2 Jun, 2005, at 19:40, Barry Watzman wrote: ... I have used Acrobat since the first beta. Your comment just proves to me that you seem to be totally clueless about the important issues in modern electronic dissemination of information, so I guess I have to explain it in more detail. I am writing this with the help of Display PDF, the engine used for the display in Mac OS X. It is much superior to the inelegant kludges that make up other graphical display systems. Adobe is a company that understands about nice font rendering and the presentation of things. That is also what Acrobat is about, it is a way to make sure that the print shop is printing your document the way you intended. That is what a PDF file is good for, and in every other respect it is an inferior format. I have been working with communication and transfer of information between dissimilar systems for the last 30 years, so I have some idea about what is beneficial and what is harmful. Doing it the simple way is often more useful than trying to add features. Using a proprietary solution is usually bad, even it it is supposed to be the most widespread and "everybody" is using it. There are exceptions, but they need to be researched and documented in each individual case. If you scan a book, you end up with bitmaps of the pages. If you stuff these bitmaps into a PDF container, the only value you add is that they are kept together in sequence. The value you subtract is that they are no longer readily available for everybody, and anybody who wants to OCR them to make any kind of index or cross reference will have to use proprietary software or get them extracted from the container they are put in. Now, if you do it the simple way, you use a suitably named directory instead of the PDF file. In that directory, you can keep individual PNGs for each page you scanned, named P000 and up (use whatever starting value is suitable to reflect the page numbers in the book). If it is structured that way, you make a subdirectory for each chapter and appendix, and place the page scans in there instead. Thus you retain the structure of the original without using any proprietary format, and everybody with a graphical display will be able to use the scanned book. There are numerous image viewers available for all platforms, many will be graphical browsers which will navigate your pages and directories rather better than an Acrobat reader. Many suitable viewers are available from open source projects, so you can build one even on platforms which have been neglected for years. The most elegant solution, though, is to use an ordinary web browser to access the pages. It is trivially simple to make a website out of this directory structure, and there are many free server-side products available to make access user friendly without any effort by the maintainer. It is in the web scenario we most clearly see the "value subtracted" nature of PDF. If I want to look at the information of page 52, I have to get the whole document. That will waste bandwidth, and it makes the server more expensive to operate. Besides, I get thrown out of the normal working mode for my web browser and into the different mode of the Acrobat plugin (if that is supported on the platform I use, otherwise it will be the standalone reader or GhostView or something). The next important feature of the open solution is that it encourages a collaborative effort to add useful thigs like indexes, cross references and even full text versions. Take a look at Wikipedia to see what it is possible to accomplish when things are kept in open, universally accessible form. A repository of technical information could be set up the same way, and it would become gradually more useful as people added their comments and index hints for the scanned pages as metainformation. To OCR the pages just for use as aids to searching and indexing would be simple, the raw OCR output could be given the same name as the scanned page just with a .txt extension. If somebody later on were to proofread and mark it up, that would lead to a .xml document. These kinds of possibilities are only available if the documents are kept in a simple, logical structure that is accessible to as many as possible, not just for reading but for further refinement. In order to avoid technical lock-in today, my preferred document format is XML with CSS styling, either with an XHTML DTD or, ideally, a DTD tailored to the usage area and reflected by the stylesheets. Bitmap images are ideally PNGs, photographs JPEG 2000, and vector images are SVG. There exists a plethora of free tools to work with, transform and generate this kind of document. The most harmful things for anybody who wants a useable, syntactical web, are lock-in formats. The worst by far is Flash, with Microsoft Office formats closely following (even when the output is supposed to be HTML), but PDF is a good third. -- -bv