從一種子像素開始，透過平均灰階度、色彩等性質檢視，將類似性質的像素逐一納入所考慮區域中，逐漸長成一個性質相似的影像區塊。-Starting from a sub-pixel by the average degree of gray-scale, color and other properties to view, each pixel of a similar nature will be included in the region considered, and gradually grow into an image block of a similar nature.