Understanding AS3 ColorMatrixFilter class

核心提示： we have no changes. Why not? because the matrix is an identity matrix.An identity matrix or unit matrix of size n is the n-by-n square matrix with o

we have no changes. Why not? because the matrix is an identity matrix.

An identity matrix or unit matrix of size n is the n-by-n square matrix with ones on the main diagonal and zeros elsewhere.

Changing the saturation

To change the saturation of an image, simply boost red component on red channel, green component on green channel and blue component on blue channel, while decreasing the other ones.

　package　{
　import　flash.display.Sprite;
　import　flash.filters.ColorMatrixFilter;
　public　class　cmf　extends　Sprite　{
　　var　cats_image:cats=new　cats();
　　public　function　cmf()　{
　　　addChild(cats_image);
　　　var　matrix:Array　=　new　Array();
　　　matrix=matrix.concat([2,-1,0,0,0]);//　red
　　　matrix=matrix.concat([-1,2,0,0,0]);//　green
　　　matrix=matrix.concat([0,-1,2,0,0]);//　blue
　　　matrix=matrix.concat([0,0,0,1,0]);//　alpha
　　　var　my_filter:ColorMatrixFilter=new　ColorMatrixFilter(matrix);
　　　cats_image.filters=[my_filter];
　　}
　}
}

Adding contrast

To add contrast, increase red component on red channel, green component on green channel and blue component on blue channel and decrease all offset values, this way