MATLAB: display RGB values of a fits image

Question

I want to read a .fits image of wide field sky and display the RGB values contained in a star. Can you please suggest a method to do so? I have used fitsread to read in the image but i am not able to show the RGB values for specific locations(star).

Answer 1

In order to do this, you'll need a proper rgb fits file. The only .fits viewer I know of, ds9, does not support saving rgb fits files, but rather as the three separate (r,g,b) fits images. You can use "getpix" from wcstools (http://tdc-www.harvard.edu/wcstools/) or scisoft (http://www.eso.org/sci/software/scisoft/) on the individual frames. Note that "getpix" returns the pixel value given an image (x,y) location. ds9 does not provide the physical image location, but rather the wcs coordinates, so you may have to convert to image coordinates before calling getpix.