Image processing apparatus utilizing pixel values of peripheral pixels adjacent the subject pixel

摘要

The present invention relates to an image processing apparatus, and to realize improved lossless compression of images more efficiently. A first predictor 11 generates a prediction signal P out of peripheral pixel values supplied from a pixel sequence generator 2. A second predictor 12 generates a prediction signal Q out of the peripheral pixel values supplied from the pixel sequence generator 2. An adder 4 subtracts the prediction signal P from the current pixel value to thereby calculate a prediction error signal M. When the prediction signal Q is greater than the prediction signal P, an inverter 14 inverts the polarity of the prediction error signal M to consequently generate a prediction error signal N. And an entropy encoder 5 allocates a code word in accordance with the prediction error signal N generated by the inverter 14.