An image quality improving device includes: a low pass filter for extracting a low frequency component from an input image signal; a subtraction unit for acquiring a high frequency component by subtracting the low frequency component extracted by the low pass filter from the input image signal; an addition unit for correcting the image quality of the input image signal by adding the high frequency component acquired by the subtraction unit to the input image signal; and a control unit. The low pass filter includes a recursive filter which executes weighted addition processing for weighted addition of the input image signal and a delay signal which has applied a predetermined delay to the output of the recursive filter, and outputs the results of the weighted addition processing as a low frequency component. When the input image signal represents a plurality of images, the control unit executes the weighted addition processing for the plurality of images using the recursive filter.
