Image encoding device, image decoding device, and program thereof
Video coding according to the disclosure of the present application includes generating a predictive signal of a target object either by means of intra-prediction or inter-prediction. The generated predictive signal of the target object then undergoes filtering to smooth out a transition of pixel signals from a neighboring block to the target block. In the disclosure of the present application, the filtering is performed only when the filtering is necessary. A parameter indicating whether to execute or not to execute the filtering is sent from the encoder to the decoder. The present application also discloses provision of multiple types of transformation processes. A selection signal is used to select one type of transformation process from the multiple types of transformation processes. Alternatively, one type of transformation process is selected according to whether to execute or not to execute the filtering.
1. An image decoding device for decoding a signal encoded by block-dividing a frame constituting a moving image, the image decoding device comprising:
a predictor circuitry configured to generate a predicted image of block unit including a prediction signal by a predetermined prediction that performs a signal prediction for each pixel signal of an original image of the block unit;
a corrector circuitry configured to
acquire a control identification signal indicating a type of selection control selected by an encoding side, wherein the type of selection control corresponds to a selection between different transformations without using a transformation selection flag that indicates a transformation selected by the encoder side,
control, based on the control identification signal, an execution and a non-execution of a modifying process on a prediction signal of a block of the predicted image, and
generate a block of a new predicted image by performing the modifying process by using the decoded neighboring signal neighboring to the block of the predicted image when executing the modifying process;
an inverse quantizer circuitry configured to reconstruct a transformation coefficient signal by performing a corresponding inverse quantization process on a transformation coefficient quantized by a predetermined quantization process as a signal encoded by block-dividing a frame constituting the moving image; and
an inverse transformer circuitry configured to reconstruct a prediction residual signal of the block unit by performing an inverse transformation process determined based on the control identification signal with respect to the reconstructed transformation coefficient signal.
2. The image decoding device according to claim 1 , wherein the inverse transformation selection controller circuitry comprises acquirer circuitry configured to acquire the control identification signal as an encoding parameter indicating whether a discrete cosine transform among the plurality of types of transformation processes is applied to the encoding side.
3. An image decoding method for decoding a signal encoded by block-dividing a frame constituting a moving image, the image decoding method comprising:
generating a predicted image of block unit including a prediction signal by a predetermined prediction that performs a signal prediction for each pixel signal of an original image of the block unit;
acquiring a control identification signal indicating a type of selection control selected by an encoding side, wherein the type of selection control corresponds to a selection between different transformations without using a transformation selection flag that indicates a transformation selected by the encoder side;
controlling, based on the control identification signal, an execution and a non-execution of a modifying process on a prediction signal of a block of the predicted image;
generating a block of a new predicted image by performing the modifying process by using the decoded neighboring signal neighboring to the block of the predicted image when executing the modifying process;
reconstructing a transformation coefficient signal by performing a corresponding inverse quantization process on a transformation coefficient quantized by a predetermined quantization process as a signal encoded by block-dividing a frame constituting the moving image; and
reconstructing a prediction residual signal of the block unit by performing an inverse transformation process determined based on the control identification signal with respect to the reconstructed transformation coefficient signal.