Bitmap尺度变换

 Bitmap bitMap = BitmapFactory.decodeFile(path);
 int width = bitMap.getWidth();
 int height = bitMap.getHeight();
 // 设置想要的大小
 int newWidth = 500;
 int newHeight = 400;
 // 计算缩放比例
 float scaleWidth = ((float) newWidth) / width;
 float scaleHeight = ((float) newHeight) / height;
 // 取得想要缩放的matrix参数
 Matrix matrix = new Matrix();
 matrix.postScale(scaleWidth, scaleHeight);
 // 得到新的图片
  bitMap = Bitmap.createBitmap(bitMap, 0, 0, width, height, matrix, true);

Bitmap转角度

Bitmap bm = BitmapFactory.decodeByteArray(imgdata, 0,imgdata.length);
Matrix matrix = new Matrix();
matrix.preRotate(270);
bm = Bitmap.createBitmap(bm, 0, 0, bm.getWidth(),bm.getHeight(), matrix, true);