Portable Document Format ( PDF ) is a cross-platform open format for electronic documents, originally developed by Adobe Systems using a number of features of the PostScript language . It is primarily intended for the presentation of printing products in electronic form. There are many programs for viewing, as well as the official paid program Adobe Reader . A significant amount of modern professional printing equipment has hardware support for the PDF format, which allows you to print documents in this format without using any software. The traditional way to create PDF-documents is a virtual printer , that is, the document as such is prepared in its specialized program - a graphic program or text editor , CAD , etc., and then exported to PDF format for electronic distribution, transfer to a printing house and etc.
| Portable document format | |
|---|---|
| Expansion | |
| MIME type | application/pdfapplication/x-pdfapplication/x-bzpdfapplication/x-gzpdf |
| Signature | %PDF |
| Developer | Adobe Systems , ISO |
| Published | June 15, 1993 |
| Latest issue | 2.0 |
| Format type | Electronic document |
| Expanded from | PostScript |
| Developed in | PDF / A , PDF / X , PDF / E, PDF / UA, PDF / VT |
| Standard (s) | ISO 32000-2 |
| Open format ? | Yes |
| Site | iso.org/standard/63534.h... |
PDF July 1, 2008 is an open standard ISO 32000 [1] [2] .
The PDF format allows you to embed the necessary fonts (line-by-line text), vector and bitmap images, forms and multimedia inserts. Supports RGB , CMYK , Grayscale , Lab , Duotone , Bitmap , several types of raster information compression. It has its own technical formats for printing: PDF / X-1a , PDF / X-3. Includes an electronic signature mechanism to protect and authenticate documents. A large amount of related documentation is distributed in this format.
Content
General information
Most often, a PDF file is a combination of text with raster and vector graphics , less commonly text with forms , JavaScript scripts, 3D graphics, and other types of elements.
The information volumes of two PDF documents that look the same on the screen can vary significantly depending on:
- embedding or linking fonts and multimedia ;
- raster image resolutions ;
- Using the built-in compression mechanism for the entire document;
- used bitmap compression algorithms.
To create a document of minimum size, you must use vector graphics and "safe" fonts. There are 14 of these fonts in total:
- Times (v3) (regular, italics, bold, and bold italics)
- Courier (Regular, Inclined, Bold, and Bold Inclined)
- Helvetica (v3) (Regular, Inclined, Bold, and Bold Inclined)
These fonts can be used without embedding in the document, since all programs must correctly display them. Any other fonts that were not embedded in the document and are absent in the system will be replaced by one of the existing ones, which may cause incorrect display of pages, the number of characters in a line and other display errors associated with the font metric .
There is MRC technology (Mixed Raster Content), which brings the capabilities of PDF to the capabilities of the DjVu format for storing scanned images with text. [3]
PDF Editing
There are special programs that allow you to edit PDF files, but their choice is much less than programs for creating or viewing PDF documents. Starting with version 0.46, Inkscape allows editing PDF [4] due to the use of the Poppler program at the intermediate stage. In 2017, PDF editing functionality was supported in the Russian program ABBYY FineReader , which previously specialized only in recognizing and converting PDF to other formats. [five]
History
At first, this format was extremely unpopular:
- Adobe's PDF reader and writer software was paid;
- PDF lacked support for external links, which made it virtually useless on the World Wide Web;
- PDF documents were larger than plain text, which meant longer loading on slow modems, which were widely used in those days;
- On slower machines, PDF documents were displayed with noticeable delays;
- there were several competing formats, such as Envoy , Common Ground Digital Paper , Farallon Replica ; even native PostScript was a competitor.
After Adobe released the free version of Acrobat Reader (later renamed Adobe Reader ) for reading PDF documents, the popularity of this format began to increase. The format of PDF files has changed several times and continues to evolve. There are several format specifications that expand each other sequentially. For each new specification, new software versions are created from the Adobe Acrobat suite. The table below shows the correspondence of versions of documents and versions of programs in which support for these documents was first introduced. You can find out the version of any PDF document by the first eight bytes by opening this document in text mode, for example, in notepad.
Adobe PDF versions
| year | document version | new opportunities | software version |
|---|---|---|---|
| 1993 | PDF 1.0 | Acrobat 1.0 | |
| 1994 | PDF 1.1 | passwords , links , streams , device-independent color rendering | Acrobat 2.0 |
| 1996 | PDF 1.2 | interactive elements, mouse event handling, multimedia types, Unicode , enhanced color and graphics | Acrobat 3.0 |
| 1999 | PDF 1.3 | digital signatures , ICC and DeviceN color spaces , JavaScript | Acrobat 4.0 |
| 2001 | PDF 1.4 | JBIG2 , transparency, OCR text layer | Acrobat 5.0 |
| 2003 | PDF 1.5 | JPEG 2000 , related multimedia, object streams, cross streams, layers | Acrobat 6.0 |
| 2005 | PDF 1.6 | embedded multimedia, 3D, XML forms, AES encryption | Acrobat 7.0 |
| 2006 | PDF 1.7 | Acrobat 8.0 | |
| 2008 | PDF 1.7, AEL3 | AES encryption with a 256-bit key | Acrobat 9.0 |
| 2009 | PDF 1.7, AEL5 | XFA 3.0 | Acrobat 9.1 |
| 2011 | PDF 1.7, AEL8 | Acrobat X (10) |
PDF software
Reading
Free :
- Evince
- Okular
- SumatraPDF
- Mozilla firefox
- Atril Document Viewer
Proprietary :
- Adobe reader
- ABBYY FineReader
- Foxit reader
- Google chrome
- PDF-XChange Viewer
- PDFMaster
- STDU Viewer
- Nitro reader
Editing
Free:
- PDFmod (Linux systems only)
- Pdfsam
- Openoffice writer
- Libreoffice draw
Proprietary:
- Adobe acrobat
- ABBYY FineReader
- Infix PDF Editor
- Master PDF Editor
- Microsoft Word 2013 and higher
- Flexipdf
- PDF-XChange Editor
- PDF-XChange Viewer (partially)
- Foxit PhantomPDF
- Nitro pro
PDF Libraries
C
Free:
- Haru
Proprietary:
- Adobe PDF Library SDK
C ++
Free:
- PoDoFo
- QPDF
Java
Free:
- - creating documents, merging or separating document (s), extracting text or other content from a document, printing, electronic signature .
- ICEpdf - view and print documents, convert to image, extract content, search in a document.
Proprietary:
- - viewing and processing documents, extracting content.
PHP
Free:
- pdfparser - PHP library to parse PDF files and extract elements like text
Notes
- ↑ PDF has become an international standard - lenta.ru
- ↑ ISO Ballot for PDF 1.7 Passed! - blogs.adobe.com
- ↑ How MRC technology reduces the size of PDFs
- ↑ Bah, T. Inkscape: Guide to a Vector Drawing Program. - Prentice Hall, 2011 .-- ISBN 9780132764148 .
- ↑ Four in one: a review of the new ABBYY FineReader 14 (Russian) , 3DNews - Daily Digital Digest . Date of appeal October 24, 2018.
Links
- PDF Specifications , including the PDF Reference for PDF 1.7, PDF 1.6 ( ISBN 0-321-30474-8 ), PDF 1.5, PDF 1.4 ( ISBN 0-201-75839-3 ), PDF 1.3 ( ISBN 0-201-61588- 6 )
- Portable Document Format in the Open Directory Project Link Directory (dmoz)