Encoding device, decoding device and program for triangle merge protection on boundary between two blocks

An encoding device that performs encoding on each of blocks obtained by dividing an image, the encoding device comprising:

• a merge predictor circuitry configured to generate area prediction images of a plurality of divided areas obtained by dividing an encoding-target block and merge areas at boundaries of a plurality of the generated area prediction images through weighted averaging to generate a prediction block of the encoding-target block;
• a transformer/quantizer circuitry configured to perform a transform process and a quantization process on a prediction residual that represents a difference between the encoding-target block and the prediction block;
• an inverse quantizer/inverse transformer circuitry configured to restore the prediction residual by performing an inverse quantization process and an inverse transform process on transform coefficients obtained by the transformer/quantizer;
• a combiner circuitry configured to combine the restored prediction residual and the prediction block to reconstruct the encoding-target block;
• a deblocking filter circuitry configured to perform a filter process on a block boundary between two blocks including the reconstructed encoding-target block and an adjacent block adjacent to the encoding-target block;
• and
• a filter controller circuitry configured to control the deblocking filter based on a position of a merged area merged by the merge predictor through the weighted averaging, wherein
• the deblocking filter is configured to perform the filter process in units of two sub-blocks across the block boundary, and
• the filter controller is configured to control the deblocking filter such that the filter process is performed on a sub-block boundary in response to the sub-block boundary between the two sub-blocks being adjacent to the merged area.