Patent ID: 7720278

Claim:
A misregister amount detection method performed by a misregister amount detection apparatus comprising the steps of: sensing printed register marks of colors and extracting inverted R image data, inverted G image data, and inverted B image data of R image data, G image data, and B image data respectively containing R as a red color component, G as a green color component, and B as a blue color component of the register marks of the colors; extracting a minimum value of pixel values of corresponding pixels of the generated inverted R image data, inverted G image data, and inverted B image data and converting the extracted minimum value of the pixel values of the pixels into a pixel value of a corresponding pixel of K image data containing K as a black color component; obtaining differential R image data by subtracting the pixel value of each pixel of the K image data from the pixel value of a corresponding pixel of the inverted R image data, obtaining differential G image data by subtracting the pixel value of each pixel of the K image data from the pixel value of a corresponding pixel of the inverted G image data, and obtaining differential B image data by subtracting the pixel value of each pixel of the K image data from the pixel value of a corresponding pixel of the inverted B image data; obtaining enhanced R image data by adding one of the pixel value of each pixel of the differential R image data and a value corresponding to the pixel value thereof to the pixel value of a corresponding pixel of the inverted R image data, obtaining enhanced G image data by adding one of the pixel value of each pixel of the differential G image data and a value corresponding to the pixel value thereof to the pixel value of a corresponding pixel of the inverted G image data, and obtaining enhanced B image data by adding one of the pixel value of each pixel of the differential B image data and a value corresponding to the pixel value thereof to the pixel value of a corresponding pixel of the inverted B image data; and obtaining a misregister amount between the colors on the basis of the pixel values of pixels of the enhanced R image data, enhanced G image data, and enhanced B image data.