US 11,991,335 B2
High-speed cell-based image compression
Kenneth A. Schmidt, Redondo Beach, CA (US)
Assigned to KYOCERA Document Solutions Inc., Osaka (JP)
Filed by KYOCERA Document Solutions, Inc., Osaka (JP)
Filed on Aug. 23, 2021, as Appl. No. 17/409,641.
Prior Publication US 2023/0068158 A1, Mar. 2, 2023
Int. Cl. H04N 1/41 (2006.01); G06T 3/40 (2006.01); G06T 9/00 (2006.01)
CPC H04N 1/41 (2013.01) [G06T 3/40 (2013.01); G06T 9/00 (2013.01)] 20 Claims
OG exemplary drawing
 
1. A computer-implemented method comprising:
obtaining an input pixel map of a digital image, the input pixel map containing a two-dimensional array of a×b pixel macro-cells;
based on analysis of pixels therein, classifying each of the a×b pixel macro-cells as P class cells suitable for substantially lossless compression or Q class cells suitable for lossy compression;
creating a first intermediate pixel map representing: (i) the P class cells from the input pixel map as is, and (ii) the Q class cells from the input pixel map with all zero values, wherein the P class cells and the Q class cells appear in the first intermediate pixel map at their locations in the input pixel map;
creating a second intermediate pixel map representing: (i) the P class cells from the input pixel map with all zero values, and (ii) the Q class cells from the input pixel map as is, wherein the P class cells and the Q class cells appear in the second intermediate pixel map at their locations in the input pixel map;
encoding the first intermediate pixel map into a first output stream by using substantially lossless compression; and
encoding the second intermediate pixel map into a second output stream by: (i) downsampling the P class cells and the Q class cells into m×n micro-cells, and (ii) serializing representations of pixels of the m×n micro-cells into the second output stream.