有时候我们需要将ImageView加载的图片去彩色,以黑白灰度显示,如qq的不在线头像。
第一种,我们可以通过将彩色bitmap图转换成黑白灰度bitmap图:
/*** 图片去色,返回灰度图片* @param bmpOriginal 传入的图片* @return 去色后的图片*/public static Bitmap toGrayScale(Bitmap bmpOriginal) {int width, height;height = bmpOriginal.getHeight();width = bmpOriginal.getWidth();Bitmap bmpGrayScale = Bitmap.createBitmap(width, height, Bitmap.Config.RGB_565);Canvas c = new Canvas(bmpGrayScale);Paint paint = new Paint();ColorMatrix cm = new ColorMatrix();cm.setSaturation(0);ColorMatrixColorFilter f = new ColorMatrixColorFilter(cm);paint.setColorFilter(f);c.drawBitmap(bmpOriginal, 0, 0, paint);return bmpGrayScale;}
第二种,利用ImageView的setColorFilter方法实现:
ColorMatrix cm = new ColorMatrix();cm.setSaturation(0); // 设置饱和度ColorMatrixColorFilter grayColorFilter = new ColorMatrixColorFilter(cm);imageView.setColorFilter(grayColorFilter); // 如果想恢复彩色显示,设置为null即可