control point generator

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michael crane

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Dec 15, 2009, 4:26:10 PM12/15/09
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how does the control point generator work ?
Does it only compare image to image with no ( lens) parameters ?
regards

MIck

DaveN

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Dec 17, 2009, 10:44:55 PM12/17/09
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I don't think you will get an answer. I asked a similar question on
the Hugin list and am catching a lot of flack for it.

PTGui Support

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Dec 18, 2009, 3:59:16 AM12/18/09
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Actually I missed the question, sorry about that.

The control point generator does take the lens settings into account so
it's important to set the lens type and (approximate) focal length
before generating control points. Any potential control points that do
not fit the lens settings will be discarded in the process.

Joost

Jeffrey Martin

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Dec 18, 2009, 8:57:32 AM12/18/09
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What a surprise :-DDDD

Jeffrey Martin

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Dec 18, 2009, 9:01:23 AM12/18/09
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I can add that the contrl point generator also takes position into
account (as far as I can tell anyway)

so if your imare are lined up roughly BEFORE you generate ctrl points
you'll get better results.

you can see this by making ctrl points, optimizing, and then making
more ctrl points. you'll get more the second time. it makes sense of
course - the more variables you have (nearly) solved the better you
can solve the unsolved ones, i guess.

there's one thing I still think could be improved with the ctrl point
generator - does it remove crappy control points? (yes i know you can
manually "remove bad control points" or manually delete the ones with
highest error which is what i've done hundreds of times) seems like an
apclean-type thing would improve the process a bit?

Hans

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Dec 18, 2009, 10:00:01 AM12/18/09
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Problem is there are 2 kinds of bad controlpoints.
1. the ones that are misplaced but not necessary giving bad errors.
2. the ones that give you large distance errors but are large because
bad optimizing. ( lack of shift optimizing for example)

There is no way for a "Dumb" software to decide which it is. Only the
human eye and intelligence can find out.

Hans

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