PanoTools NG:
RE: pseudo "scanning" a large map
Sacha Griffin 2007-Nov-30 19:08:05
There are some tutorials for this. Utilizing panotools.
Unfortunately, panotools tries to map onto a sphere.
You can fudge the situation to get some good results, but I would suggest
only using panotools
to defish your images. For best results, use a lens with the least amount of
native distortion. Like a 50mm lens.
You may not even need to defish it. Then you would setup your camera, and
not move it.
Affix your map to something flat and move that.
Then you can just use photoshop for assembling.
And if needed, when everything is aligned, you COULD save each layer to its
own file and use a blender on it.
But a mask in photoshop would probably suffice.
Since you're just doing some "scanning" of something too big for a scanner,
you probably only need 4-8 shots.
Using photoshop transforms, would be extremely quick and save yourself the
headache of getting panotools to do something it was not designed for.
Sacha Griffin
Southern Digital Solutions LLC - Atlanta, Georgia
www.southern-digital.com
www.seeit360.net
www.ezphotosafe.com
404-551-4275
404-731-7798
_____
From: #removed# [mailto:#removed#] On
Behalf Of paul womack
Sent: Friday, November 30, 2007 4:57 AM
To: #removed#
Subject: Re: [PanoToolsNG] pseudo "scanning" a large map
Bruno Postle wrote:
> On Thu 29-Nov-2007 at 13:05 +0000, paul womack wrote:
>> On a loosely related theme, I would like to use panoramic
>> techniques to make a hiresolution "scan" of a roughly
>> 36"x24" (very old, quite fragile, paper) map.
>>
>> I certainly don't have a flatbed scanner that size,
>> and a tesselated scan would on my A4 flatbed
>> would endanger the map physically.
>>
>> Are there any special difficulties here?
>
> It's more complex than a usual stitching job, but it is all doable
> with any panotools-derived tool - Look for tutorials on stitching
> 'linear panoramas'. I think you are using hugin,
Yes; I use Linux, and open-source in general for my hobbies.
> in which case
> there is a tutorial here:
>
> http://www.dojoe. <http://www.dojoe.net/tutorials/linear-pano/>
net/tutorials/linear-pano/
I saw that; I believe I can avoid some
of that complexity by situtating my pano-head a good distance"
e.g. 8 feet from the map, and using a long lens (say 100mm in 35mm terms)
and making a simple "tiled" set of photos.
Thus (I hope) emulating a super high-res camera.
> There was some more discussion of this tutorial earlier on the ptx
> list (sorry, just trying to avoid duplication):
>
> http://thread.
<http://thread.gmane.org/gmane.comp.misc.ptx/8060/focus=8082>
gmane.org/gmane.comp.misc.ptx/8060/focus=8082
Avoiding duplication is good! I certainly have
no right to demand that you re-key for my
benefit ;-)
>
>> What stitching projection should I use?
>
> Rectilinear.
>
>> One concern is maintaining "linearity" so that 1" at the edge of
>> the map is the same size(!) in my final output as 1" in the middle
>> of the map.
>
> Use horizontal and vertical control points to keep the perspective
> 'straight-on'.
Yes - that would correct any errors. Would I expect
such errors?
Thanks for your help.
BugBear
[Non-text portions of this message have been removed]
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