| 摘要 |
PROBLEM TO BE SOLVED: To prevent a character from being removed with a ground in the case of an image where the character whose density is somewhat higher than that of the ground exists on the ground with a comparatively high density value. SOLUTION: Edge amount δ is calculated by calculating difference of density between adjacent pixels for RGB data Pix with linear density by an edge amount calculating part 11, the edge amount δis converted into an adjustment coefficient S in a δMTF table 12 and NewPix=Pix+δ×S is calculated in an operation part 13. A maximum value max (Rin, Gin, Bin) of input data Rin, Gin, Bin (=NewPix) from an adaptive edge-processing part 3 is calculated in a maximum value calculating part 21, kinds of ground removal amount Rsub, Gsub, Bsub are calculated based on the maximum values (Rin, Gin, Bin), a threshold (th) and an inclination M in a ground removal amount calculating part 22 and the ground is removed by considering the density of the color in a ground removal operation part 23. |
