How can I extract RGB color values from a point or region of an image?

[mobiux]

I am working with RGB images and converting them to Grayscale and am wanting to map certain colors or color ranges to specific Grayscale values. The image info window of an image displays the RGB values of the point where the mouse is, how can I access this same info. How would I get the values for a region using the ROI tool. Say I select a ROI over a region of the image, I want to extract just the RGB values associated with the ROI. ROI to mask only accepts 8 bit images, this would work if I do it for each color plane...Any related info or suggestions are appreciated! Thanks

[unclebump]

Here is a portion of a vi that I used to extract color values from a paint color chip chart. Read in the whole image, select a location to subset(could be only one pixel if you want). Unbundle the image data out of the output cluser and get the RGB values.