Compare a VGA-Snapshot with the actual shown image

[RightChoice]

Hi all,

how can I easily compare an Snapshot with the actual shown Image on the monitor. Is it the easiest way to use a framegrabber-card and work with the IMAQ-Tool?
A extern panel is the source from the image and the sample is saved on the harddisc. If the extern panel generate an error-message and I want to recognize it and compare it with the sample.

I hope you can help me.

Best Regards

[Ben]

If I understand you correctly, then the vision approach is probably the way to go.

Try posting this question to the vision group to get better answers.

Provided your lighting is constant then you should be able to subtract the reference image from the new. If the difference is in the area of teh "error" message, you then use some of the character recognition code to read what it says.

I am not an expert in vision! Please post to the vision group.

Ben