What are some of the ways that computer vision differs from human vision?
The biggest distinction is that while when we see a photo, it is intuitive for us to distinguish a person from the background, it is comparatively harder for computers to make the distinction. This means, early computers had to use movement to distinguish which pixels on a display belonged to the object or person of interest and which were only part of a background. Furthermore, to detect movement computers had to calculate the change in color or brightness of pixels between frames whereas these things are quite simple for human vision.
What are some techniques we can use to help the computer see / track what we’re interested in?
frame differencing – comparing frames to determine movement.
background subtraction – has an original background scene, compares with captured scene to determine what is not part of the background and is the object of interest.
brightness thresholding – looking for changes in luminosity to determine the position/change in position of objects.
How do you think computer vision’s capacity for tracking and surveillance affects its use in interactive art?
It allows for the extra dimension of interaction. Many artworks, including the one with the poem’s falling letters. This means that you can take more than just key or button input sand by using computer vision to track human movements, you make the artwork more intuitive to operate (consider that people may not know you need to press a button but if you see your own image on the projector you already know how to control that shadow).