An image coding apparatus is provided with a blocking circuit for dividing an input image signal into two-dimensional blocks each comprising plural pixels; a frequency distribution verifier for calculating the average and variance from a plurality of image feature data and the frequency distribution of each feature data for each block in a predetermined period; a filter characteristic decider, a filter circuit, and an encoder. The input image signal is divided into local regions each comprising plural pixels, the image feature data of each local region is extracted, the average and the variance of the extracted image feature data are calculated from the frequency distribution of the image feature data for a predetermined period, and a filter characteristic and a quantization step are decided for each local region according to the degree of singularity of each local region.