1. An image processing apparatus that converts interlace image data into progressive image data, the image processing apparatus comprising: a detecting unit configured to detect an amount of a pixel motion between a plurality of field images included in the interlace image data; a control unit which includes a processor, configured to determine a pixel region having pixels in which the amount of each pixel motion is larger than a predetermined amount, by comparing the amount of each pixel motion detected by the detecting unit to a predetermined threshold value; a conversion unit configured to convert the interlace image data into the progressive image data; and a display output unit configured to output the progressive image data to a display apparatus, wherein, the conversion unit performs an image processing for a highlight display on the pixel region that is included in a progressive image converted by the conversion unit, and the display output unit outputs image data generated by the image processing for the highlight display together with the progressive image data to the display apparatus so as to recognizably display the pixel region by the display apparatus.