Color stain analyzing method and electronic device using the method

An electronic device comprising:

• a frequency analyzing circuit configured to receive an image signal including information about a subject, to convert the image signal into first color data which are based on a first color domain, to convert the first color data into frequency data which are based on a frequency domain, and to apply frequency weights corresponding to the frequency data to the first color data to generate processed color data;
• and
• a color difference calculating circuit configured to calculate color difference values for evaluating a color stain generated by the image signal, based on the processed color data,
• wherein the frequency weights are selected based on a relationship between sensitivity information of an observer and a change in frequency of the frequency data,
• wherein the frequency data include a luminance-frequency value corresponding to a luminance value of the first color data and a color-frequency value corresponding to a color value of the first color data, and
• wherein the frequency weights include a luminance-frequency weight corresponding to the luminance-frequency value and a color-frequency weight corresponding to the color-frequency value.