more off
clear
clf

% --------- BEGIN user-servicable parts ---------

BaseName='NGC7217';

% The next 3 numbers should be determined by knowledge of the true colour
% magnitudes of field stars.
Rhi=500;
Ghi=230;
Bhi=75;

% --------- END user-servicable parts ---------

% Load in the bands
[hdr,imgB]=fitsload([BaseName,'-B.fits']);
[hdr,imgV]=fitsload([BaseName,'-V.fits']);
[hdr,imgR]=fitsload([BaseName,'-R.fits']);

% Scale the bands
imgr=imgR/Rhi;
imgg=imgV/Ghi;
imgb=imgB/Bhi;

% Create the 3-colour array, one plane for each of RGB
img=cat(3,imgr,imgg,imgb);

% Truncate the frames to the range [0,1]
img(img<0)=0*img(img<0);
img(img>1)=0*img(img>1)+1;

% Display the image to the screen
image(img)
set(gca,'ydir','norm')

% Write the image to file.
imwrite(img,[BaseName,'-RGB.tif'],'tif')
imwrite(img,[BaseName,'-RGB.png'],'png')