gistfile1.txt

public static Bitmap decodeSampledBitmapFromResource(Resources res, int resId,
        int reqWidth) {

    // First decode with inJustDecodeBounds=true to check dimensions
    final BitmapFactory.Options options = new BitmapFactory.Options();
    options.inJustDecodeBounds = true;
    BitmapFactory.decodeResource(res, resId, options);

    // Calculate inSampleSize
    options.inSampleSize = calculateInSampleSize(options, reqWidth);

    // Decode bitmap with inSampleSize set
    options.inJustDecodeBounds = false;
    return BitmapFactory.decodeResource(res, resId, options);
}

public static int calculateInSampleSize(
            BitmapFactory.Options options, int reqWidth) {
    
    final int width = options.outWidth;
    int inSampleSize = 1;

    if (width > reqWidth) {

        final int halfWidth = width / 2;

        // Calculate the largest inSampleSize value that is a power of 2 and keeps both
        // height and width larger than the requested height and width.
        while (halfWidth / inSampleSize) > reqWidth {
            inSampleSize *= 2;
        }
    }

    return inSampleSize;
}