Method and system for see-through image correction in image duplication

A system for substantially eliminating the undesirable see-through back image problem in duplicating double-sided documents, comprising:

• a scanner for scanning a front side image from the double-sided document, the front side image having portions, some of the portions including an original front image and a see-through back image from a back side image;
• a memory unit connected to said scanner for storing at least the front side image;
• an edge amount determination unit connected to said memory unit for determining an edge amount for each of the portions in the front side image;
• a smoothing unit connected to said edge amount determination unit and said memory unit for smoothing the portions having a certain amount of the edge amount in the first process result to generate a smoothed result;
• a determination unit connected to said edge amount determination unit and said smoothing unit for initially separating the see-through back image from the original front image based upon the edge amount to generate a first process result, said determination unit further separating character portions and dot pattern portions from background in the smoothed result to leave background portions;
• an average intensity level determination unit connected to said memory unit for determining an average intensity level among the portions of the front side image;
• and
• a pitch frequency detection unit connected to said memory unit for determining a presence of a pitch frequency in the portions of the front side image,
• wherein said determination unit further separates the character portions and the dot pattern portions from the background and said correction unit corrects the intensity level only when the following conditions are met, the average intensity level being below a predetermined threshold value, the edge amount being relatively small and the pitch frequency being present, a correction unit connected to said determination unit for correcting an intensity level of the character portions, the dot pattern portions and the background portions the first process result using a predetermined conversion function so as to substantially eliminate the see-through back image.