| 摘要 |
PROBLEM TO BE SOLVED: To detect fluctuation of stripe by subjecting the image picked up from the surface of a specimen to projection processing in order to determine the projective distribution waveform in the orthogonal direction and then extracting a feature point possibly causing fluctuation of stripe. SOLUTION: When an LCD panel is inspected for fluctuation of strip, foe example, an image is picked up by means of a CCD camera and subjected to projection processing for adding a brightness value to the image in the vertical direction to produce a waveform indicative of the accumulated brightness at each position in the horizontal direction. The waveform is then subjected to smoothing and a peak point where the direction of gradient changes is searched along with an inflection point where the gradient varies significantly. The points caused by noise or the points corresponding to an invisible fluctuation of strip are then deleted from the searched peak points and inflection points. An evaluation value is calculated for the remaining significant points by a given method, based on the difference between its accumulated brightness and the accumulated brightness at a right adjacent point, and the distance between both points. |
