There are various techniques to decide the threshold for binarization of the image. But, in the image which was taken under the bad lighting condition, selection of threshold is very difficult because of the shading. So we proposed the threshold equation to decide the threshold. In this study, threshold equation was derived by the correlation of the optimum threshold values and the average density of the background part. We get these data from the uniformly illuminated images taken under various lighting conditions. To get the satisfactory result, we divided the image and threshold was set to each territory where it divided. As a result, we could obtain well binarized images. Moreover, we compare the processing time with other techniques, and make sure that our technique is more good result than others.紀要論文http://purl.org/coar/resource_type/c_650
