Image processing apparatus, image processing method, and storage medium

A method comprising:

• reading an image of an original document and generating image data;
• executing color reduction processing of quantizing color of the generated image data;
• and
• changing a pixel value of an edge pixel indicating an edge portion of an image based on the image data having the quantized color,
• wherein, in a case where the pixel value of the edge pixel is a pixel value changed by the color reduction processing to decrease a luminance, the pixel value of the edge pixel is changed to a pixel value of a pixel having a highest luminance among pixels surrounding the edge pixel, and
• wherein, in a case where the pixel value of the edge pixel is a pixel value changed by the color reduction processing to increase a luminance, the pixel value of the edge pixel is changed to a pixel value of a pixel having a lowest luminance among pixels surrounding the edge pixel.

A non-transitory computer-readable storage medium storing a program that, when executed by a computer, causes the computer to perform a method of controlling an image processing apparatus, the method comprising:

• reading an image of an original document and generating image data;
• executing color reduction processing of quantizing color of the generated image data;
• and
• changing a pixel value of an edge pixel indicating an edge portion of an image based on the image data having the quantized color,
• wherein, in a case where the pixel value of the edge pixel is a pixel value changed by the color reduction processing to decrease a luminance, the pixel value of the edge pixel is changed to a pixel value of a pixel having a highest luminance among pixels surrounding the edge pixel, and
• wherein, in a case where the pixel value of the edge pixel is a pixel value changed by the color reduction processing to increase a luminance, the pixel value of the edge pixel is changed to a pixel value of a pixel having a lowest luminance among pixels surrounding the edge pixel.