CCITT G3/G4 Compression SDK bitonal format support in LEADTOOLS

LEADTOOLS supports CCITT Group3 and Group4 industry standards for compressing bitonal (1-bit) image data. Both Group3 and Group4 encode the source image line by line. The difference between the two algorithms is in the way the two standards handle successive scanlines.

In Group3 1D, each scan line is encoded independently, whereas in Group4, scan lines are encoded with reference to the previous one, resulting in improved compression ratios. In Group3 1D, a scan line is encoded as a set of runs, each representing a number of white or black pixels, with white runs alternating with black runs. Every run is encoded using a variable number of bits, which can be uniquely identified upon decoding. This means that frequently occurring lengths of run may be encoded very efficiently, while infrequent ones cause the data to grow. For example, a white run of 2 or 3 pixels can be encoded using just 2 bits, while a run of 1000 pixels can be encoded in 25.

Group4 encoding is more complex as compared to Group3 encoding. Each scan line is compared with the previous one. Because of this, vertical features in the source image are used to achieve high compression ratios.

There is also a Group3 2D algorithm. Group3 2D is a combination of Group3 1D and Group4 compression schemes. LEADTOOLS Document and Medical toolkits can keep 1 bit images Group4 compressed in memory.

Supported compression formats click below for information on compression formats available in the LEADTOOLS SDKs

LEADTOOLS offers more compression options than any other toolkit on the market. LEADTOOLS supports industry standard and proprietary alternative compression algorithms including:

• ∗∗JPEG2000
• JPEG
• LEAD CMP
• LZW
• RLE / PackBits
• ZIPLIB
• CCITT G3/G4
• Huffman
• Arithmetic
• ∗∗JBIG
• ∗∗LEAD CMW
• LEADTOOLS ABC
• NITF
• ∗∗JBIG2
• ∗∗ABIC

This feature is included in the following products See the list above for more information on which formats are supported in each toolkit.

Pricing Structure

Product	Price	Purchase	Try
LEADTOOLS Imaging Pro	†$995		Free Trial
LEADTOOLS Vector Imaging	†$1995		Free Trial
LEADTOOLS Document Imaging	*$2495		Free Trial
LEADTOOLS Medical Imaging	*$4495		Free Trial

†Hybrid License. License includes development seat, application license, unlimited internal deployment and up to 1000 commercial desk top deployments/5 commercial production server deployments per year. Annual and multi-year unlimited deployment licenses are available for commercial deployment. Please contact oemsales@leadtools.com or call a LEAD sales representative with any questions. Click here for more information on LEADTOOLS License Agreement.

* Deployment requires runtime license. Marked toolkits require runtime licensing based on the deployment of the application you develop. Several purchase options are available. For more information, please contact oemsales@leadtools.com or call a LEAD sales representative. Click here for more information on LEADTOOLS Runtime Licensing requirements.