公开(公告)号：CA996276A

公开(公告)日：1976-08-31

申请号：CA143608

申请日：1972-06-01

Applicant: IBM

Inventor： FREI ARMIN H ,  SCHINDLER HANS R ,  VETTIGER PETER

IPC: H04N7/32 ,  H04N19/124 ,  H04N19/50

Abstract: Method and device for coding and decoding video signals employing two different modes: Delta Coding for regions of minor amplitude changes, and DPCM Coding for edges which exhibit large amplitude changes. Switching between modes is effected by the bit stream carrying the video information, with a minimum of extra marker bits. Further improvement is achieved by using a higher scanning frequency for delta coding and transferring a reduced number of bits extracted by majority selection.