| 摘要 |
<P>PROBLEM TO BE SOLVED: To detect a position of a prescribed pattern comprising a dark part and a light part in an image signal with high accuracy. <P>SOLUTION: A calculation process of a center position of the pattern and a digital filter process are executed to a luminance of each pixel. In the digital filter process, a convolution A(I, J) is calculated in each line. The convolution A(I, J) is calculated by selecting a plurality of pixels in a range of magnitude corresponding to each line pattern, multiplying the luminance of each the selected pixel by a first or second coefficient having a different code correspondingly to a white or black pattern, and finding a total value thereof. Based on a value of the convolution A(I, J), a range wherein the line pattern is present is decided in each the line. Thereafter, when combining the line pattern decided in each the line, it is decided whether a combination pattern thereof corresponds to the prescribed pattern or not. <P>COPYRIGHT: (C)2005,JPO&NCIPI |
