Portable Document Format (PDF)
If any electronic document format were to herald the onset of the paperless world, PDF would be it. PDF is a file format for creating multi-page documents with graphics, images, and text that are intended to be viewed on a wide variety of platforms. PDFs are designed to be suitable for screen display or high resolution printing.
PDF is a kind of simplification and extension of PostScript. The problem with using PostScript as a portable interchange format is that it is a little too flexible and forgiving. The PDF specification adds a layer of structure that allows for applications that depend on more information than the raw graphical data needed to render a page.[9] Here’s a rough outline of PDF’s features and improvements on PostScript:
- Font management
Type 1 fonts and TrueType fonts can be embedded in a document, so you don’t have to worry about whether the end user has the correct fonts.
To save space, you can embed only the subset of glyphs actually used.
Fourteen standard fonts are guaranteed to be available for use by any PDF viewer; these fonts can be used without being included in the document.
External fonts may be used. A font descriptor is included for each font in the document, allowing the viewer to make an intelligent substitution if an external font is not available.
- Efficient document storage
JPEG compression is used for images. LZQ and Flate compression algorithms may be applied to textual and graphic objects in the document.
The drawing instruction ...
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