I thought there might be a "function" that could be used in a script to interrogate each file to see if any pixels were coloured rather than black, white or shades of grey.
Not that I am aware of in Bridge.
In Photoshop, as I previously described one can use scripting to evaluate the Lab colour mode histogram for the A and B channels. This takes time, as each image needs to be opened, converted to Lab mode, then have the A and B channel histograms evaluated by the script. It is certainly possible, but is it really worth doing?
From what you've said I guess I'm asking for too much. Once again thanks for replying. I have uploaded four images so that you can see what I’m trying to explain. A picture is worth a thousand words! Two of images look black and white until the Saturation is turned up to 100.
By @leol30
I never said you were asking for too much – but it is a lot of work!
The main problem is that you are working with JPEG files:
1) Resaving such files can introduce further degradation, whether minor or not.
2) The lossy compression can introduce non-neutral artefacts:
In your rock image, the JPEG 8x8 pixel blocking can clearly be seen when you pump up the saturation. I would consider this a "false positive" as the image probably was/is neutral apart from the JPEG damage.
This is different to your water image, where it looks like the issue was with the original conversion from colour to gray:
There are some 8x8 blocks in the background which were introduced by the JPEG save, however, the entire water looks like an error in conversion as it is uniformly -2 in the B channel of Lab, so this would be a "true positive" result in my opinion.
My question is, why is your image processing not creating a true neutral before saving to JPEG (presuming that it isn't just a coincidence that the water wasn't neutral but slightly blue)?
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