What is High Compression PDF?
Cuminas’ High Compression PDF (HC-PDF) is technology which compresses a raster image PDF at a high compression ratio when created through Scanners and Multifunction Printers. Cuminas has applied DjVu’s state-of-the-art compression technology to HC-PDF, so now anyone can enjoy the benefit of DjVu without needing to install the DjVu Browser Plug-in. HC-PDF conforms to all PDF standards, so it can be loaded through any standard PDF reader.
Please refer to the following whitepaper for details about HC-PDF:
PDF Versions Supported by HC-PDF
HC-PDF supports PDF versions 1.4 and 1.6. HC-PDF based upon PDF version 1.6 may not be loaded by some older PDF readers, but it provides the highest compression ratio and visual quality.
Similar to DjVu, HC-PDF supports the following three types depending upon the content:
- Composite Type: This is used for color documents with text and graphics. The image is segmented by the segmentor, which realizes the highest compression ratio.
- Photo: This is used for photo images.
- Bitonal: This is used for bitonal documents.
|PDF 1.4||Composite Type: JPEG (FG/BG) + CCITT Group 4 (Mask)
Bitonal: CCITT Group 4
|PDF 1.6||Composite Type: JPEG2000 + JBIG2
File Size Comparison
The following table compares the typical file sizes of file formats with the same visual quality. The size of DjVu and HC-PDF is 1/20 of the JPEG format, and is about 1/5 Adobe Adaptive Compression.
|File Format||Number of Pages||File Size|
|Caminova HC-PDF||2||69 KB|
|Adobe PDF Adaptive Compression||2||301 KB|
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