1. An image processing apparatus, comprising: a memory storing an image processing application; a processing device configured to access the memory and implement the image processing application to cause the processing device to: calculate a value of a feature of an input frame image; compare the feature value of the input frame image with a feature value of a previous frame image to determine an area corresponding to a change in the feature value and a degree of the change in the feature value within the input frame image; and color-code the area based on the degree to generate a color-coded frame image.