Patent ID: 7796246

Claim:
A three-dimensional image measurement method for a liquid crystal display (LCD) color filter automatic grinder for measuring a three-dimensional image of a surface of an LCD color filter, the method comprising: obtaining a plurality of image sequences along an optical axis of a charge coupled device (CCD) camera; and measuring a three-dimensional focus measure of the obtained image sequences to measure a three-dimensional image of the LCD color filter; wherein the three-dimensional image of the color filter is recovered by measuring a three-dimensional focus measure in a fine cubic body around a point (x, y, z) according to the following formula: F ⁡ ( x , y , z ) = ∑ i = x - N x + N ⁢ ⁢ ∑ i = y - N y + N ⁢ ⁢ ∑ i = z - N z + N ⁢ ⁢ ▽ ML 2 ⁢ I ⁡ ( i , j , k ) wherein x=0, 1, . . . , W (an image width) y=0, 1, . . . , H (an image height) z=0, 1, . . . , K (the number of images in an image sequence) N: a window size I: intensity of an image F: a focus measurement operator.