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Unread 11-01-2012, 23:02
Jeanne Boyarsky Jeanne Boyarsky is offline
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pixel granularity with axis camera

We were reading the vision whitepaper on camera aiming to figure out whether the camera can be used for distance. The document implies things are fine.

However there is an arthmetic error in the document. On page 9, it says
Quote:
The target width measures 2 ft wide, and in the example images used earlier, the target rectangle measures 56 pixels when the camera resolution is 320x240. This means that the blue rectangle width is 2*320/56 or 11.4 ft. Half of the width is 6.7 ft, and the camera used is the M1011, so the view angle is ~47 ̊, making Θ equal to 23.5 ̊.
Half of 11.4 feet is 5.7 feet, not 6.7 feet which implies what follows is also inaccurate.

One of our team's mentors recalculated and concluded:
Quote:
Even with the best possible image, one has to be no more than 95 inches from the target for one inch of distance change to result in a one pixel change and no more than 68 inches for a 2 pixel change.
Thoughts? Is this discussed anywhere? (I did try searching.)
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