Create 4 Childs of rect

@return average color inside rect

Create 4 childs of rect

@return graphic rect;

Calc color distance between average color in rect and each pixel

find rect with largest color distance remove it from list and split it.

@return ArrayList of rect childs

get pixel from bitmap and convert it in to two-dimensional array

@param rect @param averageColor average color inside rect.

@param quadTreeRects result list

The smaller color distance, the better the output image, but longer splitting. recommended value about 5-10

The smaller the rectangle, the better the output image, but longer splitting. recommended value about 100