[GRASSLIST:9550] Re: rectifying images

[Phillip J. Allen]

Markus,

Would this alogrithm be suitable to "completely"  cover two stereo-pair 
images with all possible/likely GCP?  I am thinking of somthing to help 
make automatic DEM's from stereo-pair images!

Phil

Markus Neteler wrote:

>hi,
>
>a student of us has implemented improved versions of
>i.points and i.rectify based on previous work as published
>in our last year's Bangkok paper.
>
>The new version
>- use FFT correlation to automatically search for ground
>  control points in a user given window pair (so, just zoom
>  more or less the same zone in the master and the slave
>  image)
>- do this for the entire stripe of images
>- bad GCPs are identified and eliminated
>- run the modified i.rectify to rectify the entire stripe.
>
>We are using this to geocode historical images. I still
>have to cleanup the code to the current coding standards,
>then I need a beta tester :-)
>
>If course you can also work with just 2 overlapping images
>and enjoy the automated GCP search.
>
>Interested?
>
>Markus
>
>On Fri, Dec 16, 2005 at 03:13:03PM +0100, Wolfgang Zillig wrote:
>  
>
>>I'm not sure if this helps for my problem (perhaps I was not clear 
>>enough in my description). The problem is, that I have one original 
>>images which I want to use as reference and all others are more or less 
>>deformed but no one at the same level. So I think I will have mark my 
>>reference points in all deformed images. When I understand right 
>>grouping is good, when you have many images whith the same deformation, 
>>or am I wrong?
>>
>>Wolfgang
>>
>>Hamish schrieb:
>>
>>    
>>
>>>>I need to rectify several images in the next time. Is there a way to
>>>>automatize this procedure a little bit? I have the "original" image and
>>>>then about 10 to 20 images which needs to be corrected that they refer
>>>>to the original one. I thought of something like saving the correction
>>>>points of the original image to an file, so that I don't need to mark
>>>>again (the reference points will be the same for all images) and I only
>>>>need to specify them in the images which needs to be rectified.
>>>>  
>>>>
>>>>        
>>>>
>>>Add all the images to a group, then rectify the lot.
>>>
>>>i.group input=name[,name,...]
>>>
>>>i.rectify -a
>>>
>>>
>>>
>>>Hamish
>>>
>>>
>>>
>>>
>>>      
>>>
>
>  
>