Patent ID: 6755498
Filing Date: 2004-06-29
Classification: G06K,H04N

Abstract:
A method for determining a gray balance comprising the steps of:a. Determining values for a first primary color, a second primary color and a third primary color defining colors representative of a tonal scale; b. Determining a neutral response comprising color values representative of the tonal scale; c. Printing a first set of color patches spanning the tonal scale according to the determined values for the first primary color, second primary color and third primary color; d. Adjusting the values of the second primary color spanning the tonal scale; e. Printing a second set of color patches spanning the tonal scale according to values of the first primary color, and the third primary color used in the first set of color patches and the adjusted second primary color; f. Adjusting the values of the third primary color spanning the tonal scale; g. Printing a third set of color patches spanning the tonal scale according to the values of the first primary color and the second primary color used in the first set of color patches, and the adjusted third primary color; h. Determining actual color values for each of the printed color patches in the first, second and third sets; i. For each color patch of the first set of color patches: i. Comparing the actual color values of the second set of color patches and the corresponding actual color values of the first set of color patches to the corresponding values of the neutral response; ii. If the actual color values of the second set of color patches are closer to the corresponding values of the neutral response than the corresponding actual color values of the first set of color patches, then changing the value of the second primary color of the color patch of the first set of color patches to the corresponding value of the adjusted second primary color of the color patch of the second set of color patches, otherwise keeping the value of the second primary color of the color patch of the first set of color patches; iii. Comparing the actual color values of the third set of color patches and the corresponding actual color values of the first set of color patches to the corresponding values of the neutral response; iv. If the actual color values of the third set of color patches are closer to the corresponding values of the neutral response than the corresponding actual color values of the first set of color patches, then changing the value of the third primary color of the color patch of the first set of color patches to the value of the adjusted third primary color of the corresponding color patch of the third set of color patches, otherwise keeping the value of the third primary color of the color patch of the first set of color patches; j. Repeating steps C through I until the first set of color patches is within a predetermined range of the neutral response.