Application of PDF in Prepress and E-books (Part 2)

6, sample output

In the prepress field, proofing is an indispensable process. Whether it is the original analog printing proofing or digital proofing, they all shoulder such a mission: proofs as a basis for customers to sign, as a reference for printing, and as a means of pre-process inspection. The proof output of the PDF document has other advantages that are not available in the proof output. For example, the PDF document is usually small and can be delivered via e-mail so that the customer can use the Adobe's PressreadY tool to produce the document from the prepress company in the office. The PDF document is output on its own inkjet printer. It is worth mentioning that the current RIP allows PDF documents to be output directly on digital proofing devices.

7, trapping processing
In the printmaking of color prints, the overlapping of page elements such as texts, images, graphics, etc., occurs from time to time. When these page elements are superimposed on one another, there is a difference between them in front and rear order, and the ones that lie in the front cover the back ones. If the colors of the front object and the back object are different, an image of the same size or hollowed out appears at the corresponding position on the respective color separation sheet. In actual production, since the registration error during the printing process is unavoidable, the white or color overlap between objects in the printed matter often occurs, which interferes with reading. Therefore, by shrinking the background color area or expanding the foreground color area, the background color area and the foreground color area have a slight boundary, so as to compensate for the absolute lap joint that is not easily achieved in the printing process. The biggest problem we have encountered in PDF document processing is the trapping of PDF documents. Quark XPress can only control the trapping of page elements generated by itself, and it is incapable of controlling trapping of elements in documents imported from the outside world. In the pre-press field, PDF documents were usually separated by means of Quark×Press. Therefore, the trap information must be added to the information after the Quark×Press separation. Of course, it is also possible to add trapping information to the PDF document. For example, you can open the PDF document to be processed in Pitshop, and make the outline bold by artificial methods to make up for the possibility of future occurrence of trapping. It is now possible to perform trapping control at the RIP separation using PS Lever 3 RIP and Adobe Inproduction.

8, synthesis and separation

The new software, SePs 2 CouP, provided by Intense, allows the PDF separation files to be combined into one composite file. This software is especially useful because you want to add relevant trapping information to the Quark ×Press color separation document. The concept of color separation is particularly important when you want a PD F document to be output on an imagesetter or a plate output machine. There are a lot of softwares that can separate PDF documents. In addition to Cracker Jack provided by Lantana, and PDF-Output Pro provided by Callas, Adobe also has its own product, Inproduction, which is dedicated to software that processes PDF documents. . Unfortunately, there are still many unsatisfactory aspects of the current 0.1 version, for example, the processing speed is not as fast as people expect, but it provides enough tools for people to solve practical problems to be able to make up for this shortcoming. If the user is using PS Lever 3 RIP, the PDF file can be directly interpreted and output on the RIP using Adobe's color separation software Inproduction. If there is no separation software, you can also open the PDF document in Acrobat and output it in EPS format. Then, perform normal color separation, interpretation, and output on the RIP.

Since PDF documents are small and easy to transmit over the network, this greatly reduces the cost of prepress processing. In the PDF document, images and graphics exist in the form of EPS, which ensures the quality of the output image. More importantly, in the pre-press field, with the help of related software, there is no technical problem in outputting the PDF document in the most optimized way. Therefore, in the near future, the application of PDF in the prepress field will become more and more extensive.

Relevant information:
Electronic book features

Electronic books are the product of digital technology and refer to electronic text stored on non-paper media. The so-called non-paper media, currently refers to disk or optical disk carriers, and its electronic text is also stored on the Internet server for users to download, or in the form of read-only optical disk on the market. In general, books in the form of electronic texts should have the following basic characteristics:
1 The versatility of the product. When reading a work, the product producer should not specify which type of computer the reader must use, which operating system to use, or which specific software to use. The discs produced should be able to be read on ordinary PCs as well as on the "Apple" machine; both on Windows 9. The X/NT platform should also be compatible with the UNIX system used by the server.
2 Should not include only the text portion of the book. A good traditional book is not only a text, but a picture and text, which is particularly important for certain types of books, such as children's books, art works, engineering and technical information.
3 No additional software is required to read, especially if you do not need to purchase additional software.
4 The smaller the file size, the better. This is especially important when you need to transfer, such as reading online or sending by e-mail. The small size of the file and the time taken by the network are relatively short, which is particularly applicable to the actual situation with narrower network bandwidth in China.
5 Maintain the integrity of the file, the content is not easily tampered with, it is not easily copied or used for other illegal purposes.
6 can print. This is a function that traditional books do not have.

The file formats commonly used for writing texts are: plain text format (TXT format); Microsoft's Word format (DOC format) and related other formats, such as WPS format, WRI writer format, RTF format, etc., which can all be converted Into DOC format with similar characteristics; Web page format (HTML hypertext format). The features of these three formats are as follows:
1 plain text format: it is the most basic format, simple, low system requirements, but can only convey the text content, does not support graphics, and requires a text reader to read.
2 Word format (including other related formats): It is a widely used word processing format and can be embedded in various objects such as graphics, images, photos, and even sounds. But its purpose is to conduct word processing, so Word must use Word processing software for reading, and at the same time, it can modify the content while reading. In addition, considering the purpose of reading: compatibility between different versions of Word files (such as layout, format, etc.) is not very good, that is, there are different Word files, preferably with different versions of Word. .
3 webpage format: ie HTML format. This format is currently mainly used for electronic journals on web pages and on the Internet, and has all the features for publishing electronic books. This format needs to be read by Microsoft's Internet Explorer (Explorer) or Netscape's Netscape Navigator (Navigator). These two browsers sometimes have some incompatibility. The same article will appear in different browsers. Different visual effects. However, when it is used as an electronic book format, the main disadvantage is that the composition of the hypertext document is too cumbersome. An e-magazine sometimes consists of dozens or even hundreds of files. Any part can be extracted separately. For other purposes, it is also not conducive to the protection of works. The reason is that this format was not developed for publishing books from the beginning.

HTML is more suitable for on-line expressions. The CGI/ASP, JAVA, javascript/VBscript, and CSS methods used do not need to be connected to a database to obtain a web page, but only need to execute a program to have an effect. Even if the result of its HTML is stored, it is difficult to reliably access all the parts, and the effect of deny access can be generated by the instruction. Therefore, it is necessary to keep the web page online.

It is not difficult to see that although many CD-ROMs in China currently use the above three file formats, they are not the most ideal carriers for electronic publications. In contrast, the PDF file format developed by Adobe has advantages that other formats cannot match. It is not only small, it is easy to use, and compatibility and other functions are also quite perfect. With the continuous launch of new versions of Adobe, the functionality and use of PDF has become more mature and complete. Nowadays, the PDF file format is not only widely used in the field of CD-ROM books, electronic books, etc., but also gradually popular in China. More and more CD-ROM books, software descriptions, help files, product manuals, training and self-study tutorials All use this file format.

PDF is an abbreviation of "portable file format". Since it is generated by Adobe's Acrobat software, it is also called Acrobat format. The PDF file format is a cross-platform file format that can be run on various models and operating systems. It can encapsulate all the information in the document's text, format, font, color, resolution, links and graphics, images, sounds, and moving images in a special integrated file. Thanks to the promotion of Adobe Corporation and the advantages of the PDF format itself, PDF has now become the undisputed industry standard for the new generation of electronic text.

The most important feature of the PDF file format is its superior cross-platform functionality, which is suitable for various operating systems such as MAC, Windows, UNIX, LINUX, and OS2. It reads through its own reader and does not rely on any of the system's languages, fonts, and display modes. Compared with other traditional file formats, PDF files are smaller and can be distributed more easily through web hosting. For example, we can create a PDF file on Windows 98 on a PC, send it to your friend's "Apple" host, and then a friend's friend can read it on his UNIX workstation. And most importantly, the format, content, color, layout, etc. they see are exactly the same as your original creation, although you are using a Chinese system and others are using a Western language system.

Being able to make hypertext links is perhaps one of the most fundamental reasons why HTML text formats have become widespread. The functions of images, bookmarks, directories, indexes, and even animations and sounds are indispensable elements of electronic books. However, these functions must be linked. Like hypertext documents, PDF fully supports these features. People can read books in PDF text format like reading web pages. Publishers can achieve professional and artistic typographic design through PDF format. It supports the embedding of various types of pictures, supports various requirements of electronic publications, and has multiple browsing operations. In addition, its features include: internal and external links, page labels, zoom reading, local references, and more. PDFs can also be used to create rich and varied web files like hypertext files. They can be read online on the Internet or an intranet through a browser, and hard copies can be printed out. Compared with the hypertext format, the PDF format has only one file, and HTML is divided into a large number of texts and pictures. They are arranged in one or different directories, and the complicated relationship among them is daunting. In terms of communication, since the size of a PDF file is only about one-fifth of that of a similar hypertext document or DOC file, it is easier to transmit via electronic commerce. As the most popular electronic publishing standard format at home and abroad, PDF has unique features that other text formats cannot match. PDF files are based on the graphical nature of Postscript and can be quickly and finely printed on almost any printer that supports PPD (such as a laser printer). It is suitable for any display resolution, allowing the user to enlarge the file for viewing.