| 摘要 |
<p>A luminance value of a reference image (reference image data) and a predetermined allowance difference data are fetched (S1) and a luminance value of an updating image is fetched (S5). Check is made to determine whether luminance values of respective pixels of the updating image are within an allowable range and pixels exceeding the allowable range are extracted (S7). The reference image data value and the allowance difference data value are updated so that the extracted pixels have luminance values within the allowable range (S12). Next, the updating image is shifted by a predetermined number of pixels with respect to the reference image (S13) and check is made to determine whether the pixels of the shifted updating image have luminance values within the allowable range, so that pixels exceeding the allowable range are extracted (S14). The allowance difference data value alone is updated, so that the extracted pixels have luminance values within the allowable range (S15).</p> |
