I want to display and store an image of grayscale type as a rgb type but i want to get  
different colors for each rang of grayscale. I thought to operate this with threshold, but then lubview convert my image to 8-bit type , so I thought to change the image by insert relevant luts row , how can I get  luts like rainbow, temperature and the like 
psdeo-color can't help me because i need my image as rgb. 
thanks.