BitmapFactory.Options options =  new BitmapFactory.Options();
options.inMutable = true;
_bitmap = BitmapFactory.decodeFile(_path, options);

BitmapFactory.Options options = new BitmapFactory.Options();
options.inJustDecodeBounds = true;
BitmapFactory.decodeResource(getResources(), R.id.myimage, options);
int imageHeight = options.outHeight;
int imageWidth = options.outWidth;

public static int calculateInSampleSize(
        BitmapFactory.Options options, int reqWidth, int reqHeight) {
// Raw height and width of image
final int height = options.outHeight;
final int width = options.outWidth;
int inSampleSize = 1;

if (height > reqHeight || width > reqWidth) {

    final int halfHeight = height / 2;
    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 ((halfHeight / inSampleSize) > reqHeight
            && (halfWidth / inSampleSize) > reqWidth) {
        inSampleSize *= 2;
    }
}

return inSampleSize;
}

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

    // 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, reqHeight);

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

final BitmapFactory.Options options = new BitmapFactory.Options();
                            options.inJustDecodeBounds = true;

                            /*
                             * If set to a value > 1, requests the decoder to
                             * subsample the original image, returning a smaller
                             * image to save memory. The sample size is the
                             * number of pixels in either dimension that
                             * correspond to a single pixel in the decoded
                             * bitmap. For example, inSampleSize == 4 returns an
                             * image that is 1/4 the width/height of the
                             * original, and 1/16 the number of pixels. Any
                             * value <= 1 is treated the same as 1. Note: the
                             * decoder uses a final value based on powers of 2,
                             * any other value will be rounded down to the
                             * nearest power of 2.
                             */
                            options.inSampleSize = 2;

                            // Decode bitmap with inSampleSize set
                            options.inJustDecodeBounds = false;

                            bitmap = BitmapFactory.decodeFile(path, options);

BitmapFactory.Options options = new BitmapFactory.Options();
options.inJustDecodeBounds = true;
BitmapFactory.decodeResource(getResources(), R.id.myimage, options);
int imageHeight = options.outHeight;
int imageWidth = options.outWidth;
String imageType = options.outMimeType;