imThreshold - Creates a "binary" image with values distributed according to the threshold parameter

Calling Sequence:

	img = imThreshold(im,rate)
	
Parmeters:

	im: matrix of an input image
	rate: a value between 0 and 100,it shows the degree of threshold
	img: output image matrix

Description:

	pixels with values below the threshold ("dark") are assigned one value (e.g., black) while those 
	above the threshold ("light") are set to antoher value (e.g., white)

Example:

	im = imread("lena.png");
	img = imThreshold(im,25);