Image processing apparatus that specifies edge pixel in target image by calculating edge strength

A non-transitory computer readable storage medium storing a set of program instructions installed on and executed by a computer, the set of program instructions comprising:

• acquiring target image data representing a target image, the target image including a plurality of pixels, each of the plurality of pixels having a plurality of component values;
• generating first image data representing a first image, the first image data being one of first component data and second component data, the first component data including a plurality of first pixel values corresponding to respective ones of the plurality of pixels, each of the plurality of first pixel values being related to a maximum value among the plurality of component values of corresponding one of the plurality of pixels, the second component data including a plurality of second pixel values corresponding to respective ones of the plurality of pixels, each of the plurality of second pixel values being related to a minimum value among the plurality of component values of corresponding one of the plurality of pixels;
• calculating a plurality of first edge strengths corresponding to respective ones of the plurality of pixels using the first image data to generate first edge strength data including the plurality of first edge strengths;
• and
• specifying a plurality of edge pixels included in the target image, wherein the specifying includes binarizing the first edge strength data to generate first binary image data.

An image processing method comprising:

• acquiring target image data representing a target image, the target image including a plurality of pixels, each of the plurality of pixels having a plurality of component values;
• generating image data, the image data being one of first component data and second component data, the first component data including a plurality of first pixel values corresponding to respective ones of the plurality of pixels, each of the plurality of first pixel values being related to a maximum value among the plurality of component values of corresponding one of the plurality of pixels, the second component data including a plurality of second pixel values corresponding to respective ones of the plurality of pixels, each of the plurality of second pixel values being related to a minimum value among the plurality of component values of corresponding one of the plurality of pixels;
• calculating a plurality of edge strengths corresponding to respective ones of the plurality of pixels using the image data to generate edge strength data including the plurality of edge strengths;
• and
• specifying a plurality of edge pixels included in the target image, wherein the specifying includes binarizing the edge strength data to generate binary image data.