Detecting digital screens (PC and Mobile)

Hi everyone,

I have a project which is based on detecting the screen of PC or Mobile. Are there any common properties in digital screens? what is the best sensor or the best way to detect digital screens?
I'm doing image processing, but I want to add quality by using sensors. 

Thanks in advance

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Downunder35m9 months ago

There is no sensor for detecting screens, so please more meaningful info as otherwise it will be impossible give proper answers.