METHOD AND APPARATUS FOR REMOVING RULED LINES

Methods and apparatus are provided for removing ruled lines from a binary image containing character portions and ruled line portions, comprising the following steps. First, horizontal black runs in the bit-map image are detected and the detected black runs portions are stored as a run-length table comprising values of the horizontal start point and the length from the starting point of each black run for each vertical position. Then, based on the run-length table, black runs exceeding a predetermined threshold value are removed from the image to remove the ruled line comprising those black runs. Then, residual noise is eliminated from the image after the removal of the ruled lines. Then, in the image after the elimination of the residual noise, vertically disconnected components of a character are connected. Then, a portion of the character which is deleted by ruled line removal process is extracted from the image after the connection of vertically disconnected components of the character. Finally, the extracted portion of the character is interpolated in the image after the removal of the residual noise to restore the portion of the character removed by the ruled line removal process.