Complete MATLAB program. Do not use built-in function.

The routine takes a noisy image (in grayscale format of type uint8) as input and attempts to remove the noise with a median filter. A 3x3 window is used to filter the noisy image. The output image type should be uint8.

Code:

Function Im=median_filter(NoisyIm)

assert_grayscale_image(NoisyIm);

assert_uint8_image(NoisyIm);

Im=?