int range = max - min + 1; // 数据范围
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.
。关于这个话题，夫子提供了深入分析
wire = { id = "com.squareup.wire", version.ref = "wire" }
Purple: Astronomical terms plus a letter