P3D Re: the value of toe-in

[fj834@xxxxxxxxxxxxxxxxxxxxx (Dr. George A. Themelis)]

>My method was to zoom in close, and use the status bar of my fave graphics
>editor to read the pixel positions directly.  I figured that keystoning
>would show up most where a foreground object approached the four corners.

I would say the "two edges", not four corners.  Keystone distortion has 
an axial symmetry:  It is zero in a vertical axis that passes from the 
center of the image and it increases as we move away from this axis.  This 
makes the two edges the worse possible places for distortion.  Masking down
(vertically) a keystoned pair will help make things better.

Perhaps Gabriel can make a good ASCII drawing?

-- George Themelis


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End of PHOTO-3D Digest 2599
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