Detect if image is blurry

edit

Finally I traslated a c++ good code that I had found in internet to java and it works very well. This is my code:

BitmapFactory.Options opt = new BitmapFactory.Options();
opt.inDither = true;
opt.inPreferredConfig = Bitmap.Config.ARGB_8888;
Bitmap image = BitmapFactory.decodeByteArray(im, 0, im.length);
int l = CvType.CV_8UC1; //8-bit grey scale image
Mat matImage = new Mat();
Utils.bitmapToMat(image, matImage);
Mat matImageGrey = new Mat();
Imgproc.cvtColor(matImage, matImageGrey, Imgproc.COLOR_BGR2GRAY);

Bitmap destImage;
destImage = Bitmap.createBitmap(image);             
Mat dst2 = new Mat();
Utils.bitmapToMat(destImage, dst2);
Mat laplacianImage = new Mat();
dst2.convertTo(laplacianImage, l);
Imgproc.Laplacian(matImageGrey, laplacianImage, CvType.CV_8U);
Mat laplacianImage8bit = new Mat();
laplacianImage.convertTo(laplacianImage8bit, l);

Bitmap bmp = Bitmap.createBitmap(laplacianImage8bit.cols(),
    laplacianImage8bit.rows(), Bitmap.Config.ARGB_8888);
Utils.matToBitmap(laplacianImage8bit, bmp);
int[] pixels = new int[bmp.getHeight() * bmp.getWidth()];
bmp.getPixels(pixels, 0, bmp.getWidth(), 0, 0, bmp.getWidth(),
    bmp.getHeight());

int maxLap = -16777216;

for (int i = 0; i < pixels.length; i++) {
if (pixels[i] > maxLap)
    maxLap = pixels[i];
}

int soglia = -6118750;      

if (maxLap < soglia || maxLap == soglia) {
    Log.d(MIOTAG, "blur image");
}