This crate aims to implement the T.4 and T.6 standard of the ITU’s Telecommunication Standardization Sector (ITU-T). These documents decribe a family of encoding/decoding algorithms for monochrome i.e. black-and-white bitmaps, which have been created for fax machines.
They are also used in the Adobe PDF file format for the encoding
of monochrome bitmap images as the
/CCITTFaxDecode stream filter.
State of implementation
This crate currently implements an Encoder and a Decoder for
the Group 4 2D coding scheme specified in T.6. This is sufficient
for creating PDF documents that use
CCITTFaxDecode to draw
Type3 font glyphs. If you want to support non-negative values of
K decode parameter, i.e. Group 3 encoding, feel free to submit
a Pull Request.