The full name of PDF is Portable Document Format, which is an electronic document format developed by Adobe. This file format has nothing to do with the operating system platform, that is, PDF files are common in Windows, Unix and Apple's Mac OS operating systems. This feature makes it an ideal document format for electronic document distribution and digital information dissemination on the Internet. More and more e-books, product descriptions, company announcements, online materials and e-mails begin to use PDF files. At present, PDF file has become the de facto industrial standard of digital information.
The purpose of designing PDF file format by Adobe Company is to support cross-platform and multimedia integrated information publishing, especially for network information publishing. In order to achieve this goal, PDF has many incomparable advantages over other electronic document formats. PDF file format can encapsulate text, font, format, color, graphics and images in one file independent of device and resolution. Format files can also contain hypertext links, sounds, dynamic images and other electronic information, support super-long files, and are highly integrated, safe and reliable.
PDF files use industry standard compression algorithms, which are usually smaller than PostScript files and easier to transmit and store. It is also page independent. A PDF file contains one or more "pages", which can handle each page independently, especially suitable for multiprocessor systems. In addition, a PDF file also contains the PDF version used in the file and the positioning information of some important structures in the file. It is precisely because of its various advantages that PDF files have gradually become the new favorite of the publishing industry.
For ordinary readers, e-books made of PDF have the texture and reading effect of paper books, which can "realistically" show the original appearance of the original book, and the display size can be adjusted at will, providing readers with personalized reading methods. Because PDF files can be independent of the language, fonts and display devices of the operating system, it is very convenient to read. These advantages enable readers to quickly adapt to electronic reading and online reading, which is undoubtedly conducive to the popularization of computers and networks in daily life. Adobe Company takes PDF file technology as the core, providing a complete set of electronic and network publishing solutions, including commercial software Acrobat for generating and reading PDF files and Illustrator for editing and making PDF files. Adobe also provides font packages for reading and printing Asian characters, namely Chinese, Japanese and Korean characters.
Read PDF
You can read PDF files with Adobe's Arcobat Reader 7.0 software (free of charge). For more information, please visit the Adobe website. www.adobe.com .
E-book format of National Library of China. It uses the scanned book image as JBIG.
Standard compression (lossless compression) is a very small NLC file. NLC file is a variant of JBIG format.
No image browsing software (including software supporting JBIG format) can browse NLC files. Clarity of digital graphics
Browsers are neither convenient nor flexible to use, especially for local browsing. IE plug-in NPBook is not easy to use
The national library book reader is a local reader with Tu Tu number, which is easy to operate.
Flexible and compact, elegant interface, with a variety of book reading optimization functions, especially suitable for book length.
It's time to read.
Book reader NLC download
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