Resize a large bitmap file to scaled output file on Android

Question

I have a large bitmap (say 3888x2592) in a file. Now, I want to resize that bitmap to 800x533 and save it to another file. I normally would scale the bitmap by calling

Answer 1

Justin answer translated to code (works perfect for me):

private Bitmap getBitmap(String path) {

Uri uri = getImageUri(path);
InputStream in = null;
try {
    final int IMAGE_MAX_SIZE = 1200000; // 1.2MP
    in = mContentResolver.openInputStream(uri);

    // Decode image size
    BitmapFactory.Options options = new BitmapFactory.Options();
    options.inJustDecodeBounds = true;
    BitmapFactory.decodeStream(in, null, options);
    in.close();



    int scale = 1;
    while ((options.outWidth * options.outHeight) * (1 / Math.pow(scale, 2)) > 
          IMAGE_MAX_SIZE) {
       scale++;
    }
    Log.d(TAG, "scale = " + scale + ", orig-width: " + options.outWidth + ", 
       orig-height: " + options.outHeight);

    Bitmap resultBitmap = null;
    in = mContentResolver.openInputStream(uri);
    if (scale > 1) {
        scale--;
        // scale to max possible inSampleSize that still yields an image
        // larger than target
        options = new BitmapFactory.Options();
        options.inSampleSize = scale;
        resultBitmap = BitmapFactory.decodeStream(in, null, options);

        // resize to desired dimensions
        int height = resultBitmap.getHeight();
        int width = resultBitmap.getWidth();
        Log.d(TAG, "1th scale operation dimenions - width: " + width + ",
           height: " + height);

        double y = Math.sqrt(IMAGE_MAX_SIZE
                / (((double) width) / height));
        double x = (y / height) * width;

        Bitmap scaledBitmap = Bitmap.createScaledBitmap(resultBitmap, (int) x, 
           (int) y, true);
        resultBitmap.recycle();
        resultBitmap = scaledBitmap;

        System.gc();
    } else {
        resultBitmap = BitmapFactory.decodeStream(in);
    }
    in.close();

    Log.d(TAG, "bitmap size - width: " +resultBitmap.getWidth() + ", height: " + 
       resultBitmap.getHeight());
    return resultBitmap;
} catch (IOException e) {
    Log.e(TAG, e.getMessage(),e);
    return null;
}