Modification of grayscale

Previous maid

ColorMatrix cmgray = {0.5F, 0.5F, 0.5F, 0, 0, 0.5F, 0.5F, 0.5F, 0, 0, 0.5F, 0.5F, 0.5F, 0, 0, 0, 0, 0, 1 , 0, 0, 0, 0, 0, 1};

Ineffective. Now refer to the GrayScale algorithm in CXImage, modify

ColorMatrix cmgray = {0.299F, 0.299F, 0.299F, 0, 0, 0.587F, 0.587F, 0.587F, 0, 0, 0.114F, 0.114F, 0.114F, 0, 0, 0, 0, 0, 1 , 0, 0, 0, 0, 0, 1};