| 摘要 |
Provided are an image encoding device that has high encoding efficiency, and an image decoding device. A mapping means maps pixel signals of an object to be encoded that are configured in prescribed color space to mapped pixel signals in which redundancy between the signals is reduced. The mapping coefficients are calculated from encoded pixel signals, thereby making encoding of mapping coefficients unnecessary. Furthermore, the mapping coefficients are calculated from pixel signals of an adjacent block comprising pixels similar to the pixels of the block to be encoded/decoded, thereby reducing redundancy significantly. The mapping is applied to the pixel signals of the block to be encoded/decoded and to an area of pixels to be referred to by prediction information, thereby enabling prediction to be applied to the mapped pixel signals, and, after executing transformation/quantization, encoding and inverse transformation/dequantization are executed. The mapped pixel signals are restored to the pixel signals. |
| 主权项 |
1. An image encoding device for encoding, for each unit block, a pixel signal of a pixel to be encoded, where the pixel is configured by a predetermined color space, into a form of a mapping pixel signal mapped into a space for reducing a correlation between signals, the device comprising:
mapping means for applying, to a pixel signal to be encoded, a mapping coefficient for reducing a correlation between the signals, where the mapping coefficient is calculated from an encoded pixel signal, to obtain a mapping pixel signal; predicting means for determining prediction information for predicting a mapping pixel signal to be encoded, from the mapping pixel signal of the encoded pixel signal; compensating means for generating a prediction signal of the mapping pixel signal to be encoded, on the basis of the prediction information; difference means for performing difference processing between the mapping pixel signal to be encoded and a prediction signal thereof to obtain a prediction residual signal; transforming means for performing an orthogonal transformation on the prediction residual signal to obtain a transformation coefficient; quantizing means for quantizing the transformation coefficient in accordance with the mapping coefficient to obtain a quantization value; encoding means for encoding the quantization value and the prediction information; inverse quantizing means for performing an inverse quantization on the quantization value to obtain a transformation coefficient; inverse transforming means for performing inverse orthogonal transformation on the transformation coefficient to obtain a prediction residual signal; adding means for adding the prediction residual signal and the prediction signal to obtain an encoded mapping pixel signal; and inverse mapping means for applying the mapping coefficient, as inverse mapping, to the encoded mapping pixel signal to obtain an encoded pixel signal, wherein the mapping means calculates the mapping coefficient from an encoded pixel signal in a predetermined region including a region to which the prediction information refers, and applies the mapping coefficient to the encoded pixel signal in the predetermined referred region when the mapping coefficient is applied to the pixel signal to be encoded, and the predicting means predicts the mapping pixel signal to be encoded, from the encoded mapping pixel signal in the predetermined region by the applied mapping coefficient. |
