| 摘要 |
PROBLEM TO BE SOLVED: To detect flicker without being affected by the movement of an object, and in such a case as a frame rate is proportional to the power supply frequency of illumination light. SOLUTION: The flicker detector comprises a means 1 for integrating the pixel level of each line in one frame or field of a video image to calculate a line lightness value, a means 2 for extracting a variation period of the line lightness value in the vertical scanning direction, and a means 3 for determines that a flicker is present when a variation period falls within a specified frequency range. The extracting means 2 calculates the difference of the line lightness value caused by a variation in the vertical scanning direction for each line, counts the number of times when the same code continues in the difference, and derives a count as a variation period. COPYRIGHT: (C)2004,JPO&NCIPI |
