Hi everyone,
I need some help analyzing dorsal fur coloration in a set of hundreds of images I received. In the past, I’ve used micatoolbox for this type of analysis with RAW images, where I had the grey reflectance values, making it straightforward. However, the images I’m working with now are in JPG format and use Kodak color control patches.
I understand that if I can’t create a custom non-linear model, I might have to use sRGB, though I know that comes with risks. My biggest challenge is finding reliable standard reflectance values for these Kodak patches, which I haven’t been able to locate online.
Are these images still usable for analysis, or is there a way to extract accurate information from them despite these issues?
Here’s an example of one of the images: https://imgur.com/a/SwkxZxT
Thanks in advance for any guidance!
I hope this is helpful but it is written in semi-ignorance.
Firstly, the Kodak colour standard is dated 2007 so it is not so old. Have you tried contacting Kodak / searching their catalogue? It looks pretty close to Kodak Q14 https://www.kodak.com/en/motion/page/color-separation-guides-and-gray-scales/. Presumably the actual standard in the image is no longer available?
Secondly – this is in the field of educated guesses – traditional Kodak grey cards used by photographers were visually mid-grey ie perceptually half-way between white and black. Due to the human visual systems nonlinearity, this corresponds to ‘18% grey’. Looking at your Kodak chip chart, the grey with the distance scale might be 18% grey. https://en.wikipedia.org/wiki/Gray_card for want of a better source.