confusables.txt and NFKC disagree on 31 characters
Москвичей предупредили о резком похолодании09:45
，更多细节参见下载安装 谷歌浏览器 开启极速安全的 上网之旅。
Медведев вышел в финал турнира в Дубае17:59，推荐阅读Line官方版本下载获取更多信息
You look at a region of the image. If all the pixels are roughly the same color (below some threshold), you store the average color for the whole region as a single value. If the pixels vary too much, you split the region into four quadrants and try again.