Title :
Still-frame image transmission using DPCM/interpolative coding
Author :
Mallappa, B. ; Cox, N.R.
Author_Institution :
Dept. of Electr. Eng., Missouri Univ., Rolla, MO, USA
Abstract :
Two methods of combining DPCM (differential pulse-code modulation) and interpolation are proposed for compressing still-frame teleconferencing signals. The first method uses horizontal subsampling, DPCM, and interpolation to achieve a 4:1 compression. The other method is similar but uses vertical subsampling instead. Simulation results indicate that either method can easily achieve the required 2-b/pel data rate with negligible degradation in image quality. Conventional DPCM is shown to perform slightly better in quantitative terms when fixed-wordlength coding is used. However, the two DPCM/interpolation methods offer other advantages when used with a variable-wordlength coder.<>
Keywords :
data compression; encoding; interpolation; pulse-code modulation; teleconferencing; video signals; DPCM; differential pulse-code modulation; fixed-wordlength coding; horizontal subsampling; image quality; interpolative coding; still frame image transmission; still-frame teleconferencing signals; vertical subsampling; Bit rate; Costs; Data compression; Degradation; Hardware; Image coding; Image communication; Image quality; Interpolation; Pulse modulation;
Conference_Titel :
IEEE Region 5 Conference, 1988: 'Spanning the Peaks of Electrotechnology'
Conference_Location :
Colorado Springs, CO, USA
DOI :
10.1109/REG5.1988.15907
