DocumentCode :
1235068
Title :
Intraframe Image Coding by Cascaded Hadamard Transforms
Author :
Fukinuki, Takahiko ; Miyata, Masachika
Author_Institution :
Central Research Laboratory, Hitachi, Ltd., Tokyo, Japan
Volume :
21
Issue :
3
fYear :
1973
fDate :
3/1/1973 12:00:00 AM
Firstpage :
175
Lastpage :
180
Abstract :
Various image coding schemes have been studied for digital transmission of videophone signals. The Hadamard transform, which is now studied for the transmission of pictures such as those from satellites, has been considered too complicated for public use, though the characteristics such as the ratio of bit-rate reduction are more desirable than those of differential pulse-code modulation (DPCM). We have found a very simple scheme of the transform, where digitized videophone signals are transformed to Hadamard components all digitally just by n digital adders and some shift registers for 2nth-order transform. For example, three adders are necessary for eighth-order transform. It is extendable to two-dimensional transform with ease. We have made an experimental model running in real time. Experiments and theoretical calculation have shown that 3 bits/sample are required for good picture quality in the case of two-dimensional (4 \\times 2) th transform and 0.5 bits more for one-dimensional eighthorder transform.
Keywords :
Hadamard transforms; Image coding; Videophone signals; Adders; Circuits; Error correction; Error correction codes; Fourier transforms; Image coding; Phase change materials; Pulse modulation; Redundancy; Shift registers;
fLanguage :
English
Journal_Title :
Communications, IEEE Transactions on
Publisher :
ieee
ISSN :
0090-6778
Type :
jour
DOI :
10.1109/TCOM.1973.1091634
Filename :
1091634
Link To Document :
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