Format Description Categories
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CPC, Cartesian Perceptual Compression
Format Description Properties
- ID: fdd000007
- Short name: CPC
- Content categories:
- Format Category:
- Other facets:
unitary, binary, sampled
- Last significant update:
- Draft status: Partial (low priority for LC)
Identification and description
||CPC (Cartesian Perceptual Compression)
||The CPC specification defines both a datastream and an associated file format for a compressed, raster (bit-mapped) image, designed for scanned bitonal documents. The method is based on matching of symbols. Cartesian Products claims that files are typically 5 to 20 times smaller than bitonal TIFFs. The compression ratio increases for longer documents.
||Potentially an initial-state or middle-state format for scanned documents; more often used as final-state format.
|LC experience or existing holdings
||For instances where bitonal images reflect content adequately, open standards, e.g., TIFF_G4, are preferable.
Proprietary compression scheme. Cartesian Products makes available APIs (application programming interfaces) to facilitate development of software using the scheme.
||No specification found. An overview is at http://www.cartesianinc.com/Tech/tech-overview.html
Requires plug-in or viewer for use. Various online document supply services that serve specialized audiences use CPC files for delivery, expecting recipients to download and install the plug-in or viewer.
| Licensing and patents
Patent filed in 1991 and issued in 1994 (#5,303,313). Treated in proprietary fashion.
Depends upon algorithms and tools for decompression to read; requires sophistication and access to documentation to build tools.
|Technical protection considerations
Quality and functionality factors
||Limited to bitonal images.
|Clarity (high image resolution)
||Limited to bitonal images. Intended primarily for documents.
||None. CPC is limited to bitonal images.
|Support for graphic effects and typography
|Functionality beyond normal rendering
File type signifiers
Useful referencesURLsBooks, articles, etc.
Monday, 09-Feb-2009 11:02:26 EST