[GRASS-dev] [GSOC 2018] - Implement a series of image fusion algorithms in GRASS GIS

[Moritz Lennert]

Hi Tudor,

Great to have you on board !

On 02/03/18 10:35, Tudor-Emil COMAN (25633) wrote:
> I'm very interested in working this summer for a project I have seen 
> proposed
> on the GSOC 2018 idea page regarding the development of image fusion 
> algorithms.
> An already existing fusion algorithm is the High-Pass Filter Addition 
> technique
> implemented in the i.fusion.hpf module [1]. The scope of the project 
> would be
> to expand the capabilities of GRASS to combine data from different sensors.

As note to other developers: Tudor has already sent me off-list a patch 
to i.in.spotvgt to respond to bug #3186 [1]. I still have to test it 
before applying, but if anyone else is interested, contact me.

> 
> The first algorithm I would implement is based on Nicolas Brodu's paper 
> named
> Super-resolving multiresolution images with band-independant geometry of
> multispectral pixels [2]. The algorithm presented in this paper would 
> increase
> the resolution of certain low resolution bands by inferring some geometric
> characteristics from high resolution bands. As opposed to the already 
> existing
> HPFA fusion method, this one does not require a panchromatic band making it
> suitable for satellites that do not produce panchromatic bands.
> 
> I'm sure some other fusion algorithms are needed in GRASS-GIS that are 
> not yet
> implemented. I'm interested in suggestions about such algorithms so that 
> I can
> read about them and incorporate them into my final proposal.

Be sure to also look at the R-FUSE algorithm [2] mentioned on the GSoC 
ideas page.

In general, I think that general algorithms such as those two, that do 
not linked to sensor specificities would be great.

This said, IIRC i.pansharpen currently has limits in terms of applying 
the classical algorithms to images encoded in more than 8 bits. 
Improving this (implying changes to the underlying modules) might be 
another element of the GSoC project.

Moritz


[1] https://trac.osgeo.org/grass/ticket/3186
[2] http://oatao.univ-toulouse.fr/16629/7/wei_16629.pdf