Need help from someone working with images

I'm working with a 3-band camera with monochrome CMOS sensor. The 3 filters are not conventional RGB filters but are somewhat different that can be called as S1, S2 and S3. The captured image is the combination of these three and is converted at first to XYZ data by using a matrix (matrix 1) and then converted to RGB for display by another matrix (matrix 2). I need to take the XYZ data file, calculate the x,y values and then calculate the Lab color difference deltaE by comparing the values of the object and the image. I've saved the image file (XYZ data) as 16-bit TIFF by using matrix 1 only. I've tried to open the image by Matlab but it shows only black. I've tried ERDAS but it also failed. The images can only be opened by Photoshop. Could anyone please tell me how can I calculate the x, y values from the image. Thanks in advance!

Need help from someone working with images and colors

Photoshop opens it correctly, OK? Then use photoshop to open the image and convert it to JPEG. the you will be able to open it in matlab easily.
OK? or I have not understand your request correctly?

JPEG compresses the image. I need uncompressed image. I need to calculate the x,y value of a color in the image on the chromaticity chart.