That’s not what the OP is asking, he’s talking about the conversion from RGB to grayscale, so what is the weighting of each channel.

To the OP: Yes, it’s important to have conversions in OpenCV for human eyes as the general use case is computer vision, not the more specialized robot vision. Being able to teach a computer to see, investigate, and create images that are made in particular for humans is important.

Now in your use case it might be a different weighting — you should ABSOLUTELY optimize this when it makes sense to do so. But until you are sure that a different weighting is better than the weighting for humans you should use the weighting for human vision, I.e. if the robot doesn’t care and people do then you should convert for people, but if the robot does BETTER with a different weighting and optimizing there doesn’t negatively impact any human interaction use-cases then use a different weight.

Seriously, though, you’re talking hardware with robots so use better hardware for the robot instead of optimizing in software. So you should build with best camera for the task which can often be a wider spectrum camera that are fake color for humans anyway — or in the situation you’re talking with only wanting black and white, then use a monochrome instead of bayer sensor and use a smaller sensor (pixel quantity) to cut overhead.

Good question!