Patent ID: 6968076

Claim:
In a printing system, a closed feedback loop method for detecting defects of a printed image to analyze print quality of the printed image, said method comprising the steps of: (a) generating a half-tone image having one or more half-tone values; (b) printing the half-tone image; (c) scanning the printed half-tone image to obtain half-tone values for the half-tone image printed wherein the half-tone values of the printed half-tone image are fed back to the printing system in a closed loop manner; and (d) comparing the printed half-tone image to the originally generated half-tone image by, (d 1 ) determining a half-tone value of printed half-tone image for each pixel; (d 2 ) calculating differences of half-tone values between the printed half-tone image and the originally generated half-tone image on a pixel-by-pixel basis; (d 3 ) examining the difference of a pixel to determine whether the pixel of the printed half-tone image falls into a defect; and (e) analyzing the comparison of the printed half-tone values to the original half-tone values to determine print quality of the printed half-tone image.