| 摘要 |
<p>In a sensed image of an object having a tridimensional form such as a cylinder, prism or the like, angles at which an illumination device shines on and an image sensing device senses each part of the surface of the object vary with each position, whereby distribution of brightness problem arises. The distribution of brightness is substantially uniform in a lengthwise direction and variable in a widthwise direction. A line in a direction of crossing the object is specified on an image sensing plane, whereby the distribution of brightness on this line is obtained. The distribution of brightness is extended in the lengthwise direction of the object, whereby a two-dimensional shading pattern is obtained. This shading pattern represents the distribution of brightness on an image of the surface of the object. Accordingly, this shading pattern data is subtracted from image data of the object, whereby shading correction is performed, so that the distribution of brightness caused by the tridimensional form of the object can be removed. <IMAGE></p> |
