Bitmap 缩放

public static Bitmap ResizeBitmap(Bitmap bitmap, int newWidth) {
int width = bitmap.getWidth();
int height = bitmap.getHeight();
float temp = ((float) height) / ((float) width);
int newHeight = (int) ((newWidth) * temp);
float scaleWidth = ((float) newWidth) / width;
float scaleHeight = ((float) newHeight) / height;
Matrix matrix = new Matrix();
// resize the bit map
matrix.postScale(scaleWidth, scaleHeight);
// matrix.postRotate(45);
Bitmap resizedBitmap = Bitmap.createBitmap(bitmap, 0, 0, width, height,
matrix, true);
bitmap.recycle();
return resizedBitmap;
}