[gdal-dev] GSoC Image Correlator

[Dmitry Baryshnikov]

27.08.2012 20:12, Frank Warmerdam пишет:
> On Mon, Aug 27, 2012 at 11:50 AM, Even Rouault
> <even.rouault at mines-paris.org> wrote:
>> Making algorithm work with imagery that is piece-wise loaded can be very
>> complicated indeed. And if you try to correlate images that are taken by sensors
>> that have very different angles, then you could need to correlate parts that are
>> not at all at the same position in the 2 images.
> Even,
>
> I think it will actually not be too hard to remove this problem
> with loading the whole image.  It seems that the reference
> point objects (the somewhat poorly named GDALFeaturePoint)
> stores a "descriptor" representation of the point with it and so
> after these are collected from one of the images it is not
> necessary to keep the original image in memory.
>
> I'm still not sure how to handle the image scaling and
> conversion to a luminosity image more smoothly.
>
> Best regards,
There are several ways to use not the whole images (prevent load full 
image to the memory).
1) Use aerial images metadata (e.g. 
ftp://www.aerialrobotics.eu/winter-high-overlap/trace.txt.TRIG1-001.pix4d.dat) 
to get overlapped areas or part of this areas
2) Use overviews to gather points, and make their placement more 
accurate on full size image parts
3) May be OpenCL or some parallel threads
4) Gather small amount of points, and use them to make inaccurate 
orientation, and after make more accurate feature points gathering on 
overlapped areas, etc.

But I think, that by now the block images (>2) points adjustment is next 
step to create single seamless image.

Best regards,
Dmitry