An image processing device comprising: a feature amount calculating module configured to calculate a feature amount indicating features of an input image for each of first blocks of pixels constituting the input image, the feature amount corresponding to a fluctuation degree of pixel values between adjacent pixels of each of the first blocks; a determining module configured to sequentially select a processing target block as a processing target from the first blocks to determine whether the feature amount of the processing target block is equal to or smaller than a predetermined threshold; and a feature amount interpolating module configured to interpolate, when the determining module determines that the feature amount of the processing target block exceeds the threshold, feature amounts at respective positions within the processing target block by using an interpolation coefficient, and not to interpolate, when the determining module determines that the feature amount of the processing target block does not exceed the threshold, the feature amounts at the respective positions within the processing target block by using the interpolation coefficient, wherein the interpolation coefficient is based on a positional relationship between the processing target block and an adjacent block adjacent to the processing target block, and the feature amount interpolating module changes a condition of the positional relationship as a standard of the interpolation coefficient in accordance with whether the feature amount of the adjacent block is exceeding the threshold or not, the change resulting in employing different separated distances for computing the interpolation coefficient between each respective processing target block and each respective adjacent block in accordance with whether the feature amount of the adjacent block is exceeding the threshold or not. a feature amount calculating module configured to calculate a feature amount indicating features of an input image for each of first blocks of pixels constituting the input image, the feature amount corresponding to a fluctuation degree of pixel values between adjacent pixels of each of the first blocks; a determining module configured to sequentially select a processing target block as a processing target from the first blocks to determine whether the feature amount of the processing target block is equal to or smaller than a predetermined threshold; and a feature amount interpolating module configured to interpolate, when the determining module determines that the feature amount of the processing target block exceeds the threshold, feature amounts at respective positions within the processing target block by using an interpolation coefficient, and not to interpolate, when the determining module determines that the feature amount of the processing target block does not exceed the threshold, the feature amounts at the respective positions within the processing target block by using the interpolation coefficient, wherein the interpolation coefficient is based on a positional relationship between the processing target block and an adjacent block adjacent to the processing target block, and the feature amount interpolating module changes a condition of the positional relationship as a standard of the interpolation coefficient in accordance with whether the feature amount of the adjacent block is exceeding the threshold or not, the change resulting in employing different separated distances for computing the interpolation coefficient between each respective processing target block and each respective adjacent block in accordance with whether the feature amount of the adjacent block is exceeding the threshold or not.