Checking text on image colour contrast compliance (when a colour gradient is applied)

Hello,

Please would anyone be able to recommend a good tool to check contrast on the brand story images that have a filter applied. We currently have a homepage image slot which applies a darker colour gradient over an image to allow the text on top of it to stand out.  The text can also be in different sizes.

I've tried WCAG contrast checker but that doesn't seem to allow for the gradient and tried Chrome colour contrast analyser instead. I don't think that gives me a definitive picture on whether I am compliant other than the contrast on some text has a better outline than other bits of text.

If there's any other options people can suggest that would be amazing!

Kind regards
Louise

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