**3.4 Quality checking of filtered image**

PSNR value is calculated using Mean Square Error (MSE) approach:

$$PSNR = \frac{1}{mn} \sum\_{y=1}^{m} \sum\_{x=1}^{n} \left[ f\left(x, y\right) - b\left(x, y\right) \right]^2 \tag{4}$$

Where *f xy bxy* ( , and , ) ( ) are original image and retrieved image respectively and m, n denotes size of images.
