Group 4 compression
Encyclopedia
Group 4 compression, usually abbreviated as G4, is a method of image compression
used in Group 4 fax machines, defined in the ITU-T
T.6 fax standard. It is only used for monochrome
(black and white) images. G4 compression is also available in the TIFF image file format, as well as in the PDF document format.
Image compression
The objective of image compression is to reduce irrelevance and redundancy of the image data in order to be able to store or transmit data in an efficient form.- Lossy and lossless compression :...
used in Group 4 fax machines, defined in the ITU-T
ITU-T
The ITU Telecommunication Standardization Sector is one of the three sectors of the International Telecommunication Union ; it coordinates standards for telecommunications....
T.6 fax standard. It is only used for monochrome
Monochrome
Monochrome describes paintings, drawings, design, or photographs in one color or shades of one color. A monochromatic object or image has colors in shades of limited colors or hues. Images using only shades of grey are called grayscale or black-and-white...
(black and white) images. G4 compression is also available in the TIFF image file format, as well as in the PDF document format.