US 6,188,796 B1Granted

Picture encoder, picture decoder, picture encoding method, picture decoding method, picture encoding program recording medium, and picture decoding program recording medium

AssigneeMatsushita Electric Industrial Co., Ltd.

InventorShinya Kadono

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Abstract

It is an object to encode an image signal or a shape signal more efficiently than the prior art. As a means to accomplish the object, the change pixel detector 2 receives the input signal 1 as an input signal and detects the pixel which changes the two-valued pixel value. Further, the change pixel predictor 4 also reads out the reference image stored in the memory 3, and predicts the change pixel of the particular input signal. The difference value calculator 5 subtracts the output of the change pixel predictor 4 from the output of the change pixel detector 2. The difference value rounder 7 compares the tolerance value e and the prediction error D, and outputs x which requires the minimum bit number for being encoded in the value D−e≦x≦D+e. The output of the difference value rounder 7 is encoded by the decoder 8 to become the encoded signal 9. Also, the output of the difference value rounder 7 is added in the difference value adder 11 to the predicted pixel 4 of the predicted pixel predictor 4, whereby the change pixel is calculated, and in the change pixel decoder 10, the respective pixels from the already decoded pixel indicated by the change pixel predictor 4 to the change pixel is decoded to be stored in the memory 3.

Claims3

Dependent claims

An image decoding apparatus for receiving and decoding an encoded signal, comprising:

first decoding means for decoding an encoded signal to obtain a difference value of a pixel value signal, and for outputting the obtained difference value as a decoded pixel value difference value;
calculation means for adding the decoded pixel value difference value and a compensated pixel value signal, and for outputting the result of the addition as a decoded pixel value signal;
second decoding means for decoding the encoded signal to obtain a motion vector of the pixel value signal and a motion vector of a shape signal, and for outputting these motion vectors as a decoded pixel value motion vector and a decoded shape motion vector, respectively;
first motion compensation means for compensating a pixel value signal of a reference image using the decoded pixel value motion vector, and for outputting the result of the motion compensation as the compensated pixel value signal;
second motion compensation means for compensating a shape signal of the reference image using the decoded shape motion vector, and for outputting the result of the motion compensation as a compensated shape signal;
and
third decoding means for decoding the input encoded signal with reference to the compensated shape signal, and for outputting the decoded signal as a shape signal.

4 more elements

Dependencies are inferred from the claim text.