An image processing circuit has a color information converter configured to convert image data including a plurality of color information into luminance data and color difference data, an activity detector whether amount of activity predetermined according to differences between the luminance data in a plurality of pixels in each of pixel blocks and differences between the color difference data in the plurality of pixels exceeds a predetermined first threshold value for each pixel block including a plurality of pixels adjacent to each other, and a encoding unit configured to perform a first encoding process by generating m (m is an integer of three or larger) representative values corresponding to the luminance data and the color difference data in the plurality of pixels in the pixel block that the activity detector determines to exceed the first threshold value, and perform a second encoding process by generating n (n is an integer of two or more and the integer larger than m) representative values corresponding to the luminance data and the color difference data in the plurality of pixels in the pixel block that the activity detector determines not to exceed the first threshold value, to generate encoded data.