Sometimes I get just all ate up about making a tool.
I wanted to see how my calibrated camera profile looked in the xyY plot. I found and printed a nice depiction of the empty plot and drew the triangle, but it was really big, taking in a bunch of “imaginary” space. Thought my math was suspect, got out a spreadsheet, but things led to things:
http://glenn.pulpitrock.net/xyY.html
Uses a SVG file of the xyY plot in a web page that allows you to enter either a XYZ or xyY matrix and plots the triangle. Also, there’s a exiftool paste box where you can paste the output of something like this:
exiftool -FileName -RedMatrixColumn -GreenMatrixColumn -BlueMatrixColumn sRGB-elle-V4-srgbtrc.icc
which looks like this:
File Name : sRGB-elle-V4-srgbtrc.icc
Red Matrix Column : 0.43604 0.22249 0.01392
Green Matrix Column : 0.38512 0.7169 0.09706
Blue Matrix Column : 0.14305 0.06061 0.71393
Click “Parse to XYZ” and the XYZ matrix above is filled. Click “Compute xyY”, and the xyY matrix to the right is calculated and filled. Over there, click the “Plot xyY” button, and the triangle is drawn on the plot. You can do this up to five times to plot different profiles.
Like all my creations, it’s a hack. Particularly, if anyone notices coordinate errors, let me know, the profiles are plotted in a weird sort of device space based on the layout of the original graphic, and my math may not be pristine.
Back to my original objective, my camera profile plot extends past the graphic, so I still have some work to do…