1、资源文件转bitmap
Bitmap bitmap = BitmapFactory.decodeResource(getResources(), R.drawable.admin, null);
2、相册URi转bitmap

Bitmap bitmap = BitmapFactory.decodeStream(getActivity().getContentResolver().openInputStream(uri));

3、bitmap转圆形图片

public static Bitmap makeRoundCorner(Bitmap bitmap) {int width = bitmap.getWidth();int height = bitmap.getHeight();int left = 0, top = 0, right = width, bottom = height;float roundPx = height / 2;if (width > height) {left = (width - height) / 2;top = 0;right = left + height;bottom = height;} else if (height > width) {left = 0;top = (height - width) / 2;right = width;bottom = top + width;roundPx = width / 2;}Bitmap output = Bitmap.createBitmap(width, height, Bitmap.Config.ARGB_8888);Canvas canvas = new Canvas(output);int color = 0xff424242;Paint paint = new Paint();Rect rect = new Rect(left, top, right, bottom);RectF rectF = new RectF(rect);paint.setAntiAlias(true);canvas.drawARGB(0, 0, 0, 0);paint.setColor(color);canvas.drawRoundRect(rectF, roundPx, roundPx, paint);paint.setXfermode(new PorterDuffXfermode(PorterDuff.Mode.SRC_IN));canvas.drawBitmap(bitmap, rect, rect, paint);return output;}