imconvert - overturn an image in a certain diretion

Calling Sequence:

	img = imconvert(im,my_select)
	
Parmeters:

	im: matrix of an input image
	my_select: select a manner for converting
	img: output image matrix

Description:

	This function provides three manner for fast overturn.
	1) horizontal 180
	2) deasil 90
	3) anticlockwise 90

Example:

	im = imread("lena.png");
	img = imconvert(im,2);