For everyone who seems to be getting false negatives, it's because you're tracing a space too large. I was initially getting robot returns, but it seems to hav

For everyone who seems to be getting false negatives, it's because you're tracing a space too large. I was initially getting robot returns, but it seems to have a higher tolerance for not binding the entire target, rather than trying to get the entire thing and having non-target space in the enclosure. With that out of the way...this isn't safe. Interesting idea, but not safe. All that's needed is an algorithm that finds the object existing in both images. This is trivial with your current setup because size doesn't matter, recognizing two clocks is pretty easy even if one takes up a full picture and the other takes up a corner. Some possibilities, and problems with each: 1. If you try a more rigorous system, where there's two pictures full of images in both, then you might have a better chance. But you'll still be giving text instructions to specify which image is the one you need to trace, and this can be automated as stated above. As soon as you state the word of the image, it's going to be algorithm-able, unless you make the image so blurry or incomprehensible as to fool both machines and humans, which defeats the purpose. 2. You could specify nothing, and instead tell the human to trace two matching objects. Regardless of whether or not there's more than one matching set, you can still automate this and pass with a machine. I think this is an interesting, and perhaps capable idea, but it's far away from having any practical or secure utility.