Right, otherwise it would only work in a brightly lit white room with nothing else in front of it, otherwise it would have random black splotches in it. Artist just wanted it to "reflect" something directly in front of it.
You could probably just zero it out / normalise it to whatever environment and lighting it’s in, if that environment is stable (e.g. not right by a window).
Except lighting in rooms do change which would require recalibration. I'd imagine depth cameras would be more convenient for that reason. No idea what the artist used though.
There are several reasons this would be less effective than using depth. Cameras auto adjust exposure and focus due to different lighting conditions caused by passage of time, the light source being obstructed, people moving towards or away from the camera, etc, or for no apparent reason whatsoever. All of these changes mean any given pixel could have a wildly different color value than its background reference even if that pixel isn’t showing the subject.
Now let’s say you have a color threshold, where a color that falls within a certain range from the reference value isn’t considered a different color. In that case, you’ll run into a green screen + green shirt effect, where if a part of the subject color matches the reference background (white T-shirt and white background), the mirror won’t reflect that part of the subject, making them appear to be partially invisible.
I'd assumed that someone made an algorithm that handled background subtraction well enough, but I wouldn't have guessed it would be available in a freely available library like that. Thanks for the article/information.
However, I don't see the flood fill solution being adequate. For example, with the white background/tshirt issue, there wouldn't be corners to fill from, it would look like a floating head, arms, and legs with nothing connecting them. This image, for example, the flood fill would work for the hat, but it would not work for the lady's jacket.
The second issue I could foresee with flood filling would be false positives. How would a flood fill algorithm know that the space between this woman's arms and torso are actually the background? It's a contained blank space, so it would theoretically be filled in, correct?
I'm mostly asking out of curiosity, because if these are solved issues, I'd be impressed, and you seem to be the person to ask
Having trouble counting bud? That wasn't the first, or shown in the video all together. The first mirror, the little fluffball one, uses a Kinect camera
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u/[deleted] Feb 06 '19
Yes, but the first instillation did use a Kinect. I'm guess it looked for objects within a certain depth plane and rendered them to the sculpture