Patent ID: 6411733
Filing Date: 2002-06-25
Classification: G06K

Abstract:
A method for separating types of objects present in an image, the method comprising steps of:a) inputting the image having objects including character type objects stroke type objects and blob type objects; b) generating a first bitmap representing the image; c) determining which of the objects of the image are of the character type by comparing predetermined decision criteria to data obtained from the first bitmap by: i) performing boundary contour tracing on the objects represented in the first bitmap to obtain a contour of each of the objects, ii) measuring a width and height of each contour based on a boundary box thereof, iii) measuring a perimeter of the each contour, iv) measuring an area of the each contour, v) determining a ratio of the perimeter to the area for the each contour, and vi) measuring a wiggliness of the each contour; d) separating character type objects from the first bitmap to obtain a second bitmap, having only characters represented therein, and a third bitmap; e) performing Nâˆ’1 thinning steps on the third bitmap to obtain a fourth bitmap; f) copying the fourth bitnmap to obtain a fifth bitmap; g) performing another thinning step on the fourth bitmap; h) removing all non-interior pixels of the fifth bitmap to obtain a sixth bitmap; i) performing an image morphology based dilation on the sixth bitmap to restore pixels eroded by the thinning and removing steps and obtain a seventh bitmap; j) performing a bitwise boolean operation between the first bitmap and the seventh bitmap to obtain an eighth bitmap having only blob type objects represented therein; k) performing a bitwise boolean operation between the fourth bitmap and the eighth bitmap to obtain a ninth bitmap; and, l) performing a tracing operation on the ninth bitmap to obtain a tenth bitmap having only stroke type objects represented therein.