Mosaic- mosaic the image

Calling Sequence:

	img = Mosaic(im,n)
	
Parmeters:

	im: matrix of an input image
	n: mosaic paremeter ,the larger ,the blurrier      (5<=n<=20)
	img: output image matrix

Description:
	
	mosaic the image

Example:
	im = imread("lena.png");
	img = Mosaic(im,8);