@article{oai:u-ryukyu.repo.nii.ac.jp:02001628,
 author = {山川, 毅 and 山城, 毅 and 渡久地, 實 and Yamakawa, Tsuyoshi and Yamashiro, Tsuyoshi and Toguchi, Minoru},
 issue = {63},
 journal = {琉球大学工学部紀要},
 month = {Nov},
 note = {Binarization of character image is very important preprocessing for automatic recognition of characters or signs. As for the image that was shot with a CCD camera, a shadow results due to lighting unevenness. To decreace the influence of the shadow, we divided the character image in some small area automatically due to its lighting unevenness. Each small area was set up in different threshold individually. The linear functions were used to set up the threshold easily. We improved the linear functions, and could obtained the better binarized image. We also compared our research with other methodology called the p-tile method, and our method showed more effective for binarization., 紀要論文},
 pages = {63--68},
 title = {シェーディングのかかった文字画像の二値化},
 year = {2002}
}