Extract features from reddish videos

I have some videos like this video. I want to extract the feature from these videos. Each video has a level value(like 25.1 mmol/L). After extracting the feature I want to apply Machine Learning methods to estimate the glucose level.

Questions are:

• Which Image processing techniques will be appropriate for extracting feature?
• How can extract features with image processing techniques? (For convenient, please share a sample code)
• How can I apply Deep Learning to estimate glucose level?

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