Alain <ele### [at] netscapenet> wrote:
> The width in unit of a pixel at a given resolution depends on at least two
> things: The field of view AND the distance of the object from the camera. As the
> distance between any object and the camera change from object to object, and
> even for a given object, in any image you can have 1 pixel that covers 0.001
> unit next to one that covers 100 units, or even more.
> What you can calculate is the angular width of a pixel.
>
> --
> Alain

I agree that perspective is going to change the actual number of units that the
pixel corresponds to for each object in the field (closer objects look bigger
than far away objects), but that isn't really the question that I am asking.
Your last statement is right, but the issue becomes that to use the perspective
transformation in a stereo algorithm, you need to know what distance the angular
width corresponds to in the image plane. This value will change only based on
the parameters of the camera, not what you are imaging. From the last few
exchanges with alphaQuad I figured out what I need to know. Basically, the
pixel width is related to the focal length of the camera, not just right and
up.(Thanks aq). When I get a chance I may try submitting a patch to the
documentation for camera that may help make things more clear. Or perhaps
everyone else understands and I'm just retarded... :-P

Thanks,
~Carl

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