从各个角度均匀地裁剪位图

Question

I have a bitmap with width 720 and height 1020 I want to crop all four corners of the bitmap with the same value say 50. So 50 from top, left, bottom and right. Here is how I have tried this in my code

sourceImg = Bitmap.createBitmap(sourceImg, 50,
                            50, sourceImg.getWidth() - 50, sourceImg.getHeight() - 50);

The top and left seem to crop properly but the bottom and right do not.

Answer 1

You should use the calculation below. Width and height are decreased by corner value (half from each side).

sourceImg = Bitmap.createBitmap(sourceImg, 
    corner/2, 
    corner/2, 
    sourceImg.getWidth() - corner, 
    sourceImg.getHeight() - corner);