Android位图掩码颜色,删除颜色

这适用于从位图中删除某种颜色.主要部分是使用AvoidXfermode.如果尝试将一种颜色更改为另一种颜色,它也应该工作.

我应该补充说,这回答了从位图中移除颜色的问题标题.具体的问题可能更好地解决了使用PorterDuff Xfermode像OP所说.

// start with a Bitmap bmp

// make a mutable copy and a canvas from this mutable bitmap
Bitmap mb = bmp.copy(Bitmap.Config.ARGB_8888,truE);
Canvas c = new Canvas(mb);

// get thE int for the colour which needs to be removed
Paint p = new Paint();
p.setARGB(255,255,0); // ARGB for the color,in this case red
int removeColor = p.getColor(); // store this color's int for later use

// Next,set the alpha of the paint to transparent so the color can be removed.
// This Could also be non-transparent and be used to turn one color into another color            
p.setAlpha(0);

// then,set the Xfermode of the pain to AvoidXfermode
// removeColor is the color that will be replaced with the pain't color
// 0 is the tolerance (in this case,only the color to be removed is targetted)
// Mode.TARGET means pixels with color the same as removeColor are drawn on
p.setXfermode(new AvoidXfermode(removeColor,AvoidXfermode.Mode.TARGET));

// draw transparent on the "brown" pixels
c.drawPaint(p);

// mb should Now have transparent pixels where they were red before