A method for coding a picture segmented into a plurality of blocks. The method decodes the coded blocks to produce a reproduced image. A filter selection parameter determines a threshold value for each quantization parameter, so as to change between a mode to effect coding distortion removal by a filter and a mode not to effect the coding distortion removal. The determined filter selection parameter is coded. A difference between pixel values of pixels in the adjacent blocks on both sides of a boundary between adjacent blocks forming the reproduced image is compared with the determined threshold value determined by the filter selection parameter, and the coding distortion is removed using the filter when the difference is smaller than the threshold value, and not removed when the difference is larger than the threshold value.