
IPT – Image Perspective Transformation (1996) - njn
http://www.fmwconcepts.com/fmw/ipt.html
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drzaiusx11
I once used this technique to make a 2D pseudo-lidar sensor from a camera
mounted on a indoor vehicle, it worked fairly well when used on uniformly
textured flooring. After transforming the camera input image using an IPT, you
could do some basic trig to figure out the distances away from the camera to
non-floor objects.

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tylerflick
This is really cool. Does anyone have links to the math/code behind this?

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web007
The first few are simple, photograph + DEM (digital elevation model) or DTM
(digital terrain model) aka height map will give you a 3D landscape with
photo-accurate texture. They add manual CAD modeling in the later images, and
that gives them the extra detail they need for 3D buildings / structures.

For the interior, it's a lot more impressive. They're doing photogrammetry or
SLAM equivalent, reconstructing depth from stereo photographs and stitching
multiple pairs together to generate a scene. They're also adding CAD in that
case, as you can see with the wireframe for the generator.

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JadeNB
The title is missing a right parenthesis after the date
[https://www.xkcd.com/859](https://www.xkcd.com/859) . EDIT: I originally put
one in this comment, but then realised that that would be even worse once the
title was fixed ….

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richardpenner
Great stuff. Would it kill this site to allow for even just the tiniest bit of
context for why a 22 year old article is being posted? Also it looks like
fmwconcepts.com has come up on Hacker News a few times for Fred's ImageMagick
scripts. But has anyone found the code to do the perspective transformation
discussed here?

