GSoC 2015_OSSIM project

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GSoC 2015_OSSIM project

Martina Di Rita
Dear OSSIM dev community,

I am Martina Di Rita, a PhD student at Geodesy and Geomatics Division, "Sapienza" University of Rome. I have developed a PlugIn to OSSIM for DSM generation from an optical stereo-pair in the framework of the last Google Summer of Code.

I have seen that OSGeo is a GSoC mentoring organization also this year, that's great!

I have checked the OSGeo GSoC wiki page and I have seen that so far there are no OSSIM ideas in... there is some reason? Is OSSIM involved this year in the GSoC?

I would like to propose a project for improve and develop the PlugIn I have created for the last GSoC.

My idea was to improve and edit where necessary the PlugIn for DSM generation (I have named it DATE - Digital Automatic Terrain Extractor) and, starting from what I have already done, extend it and enable it to process also a triplet and not only a stereo-pair (since we are witnessing a quick increase of tri-stereo satellite sensors). Furthermore I would like also to include the possibility to use SAR imagery for DSM stereo reconstruction (i.e. radargrammetry) in addition to the "optical option" already developed.
Finally, I would love to be able to "plug" the PlugIn in the OSSIM library in order to make it actually available for everyone.

Let me know what do you think about.

Kind regards,

Martina Di Rita

--
Martina Di Rita, PhD Student                               
Geodesy and Geomatics Division   
University of Rome "La Sapienza"
via Eudossiana, 18 - 00184 Rome Italy

Phone <a href="tel:%2B%2B39%200644585087" value="+390644585087" target="_blank">++39 0644585087
E-mail martina.dirita@...


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Re: GSoC 2015_OSSIM project

Mark Lucas-4

Martina

We would be happy to work with you on this.
I am currently returning from foss4gna 
Let me know what you need

Mark
Sent from my iPhone

On Mar 13, 2015, at 10:00 AM, Martina Di Rita <[hidden email]> wrote:

Dear OSSIM dev community,

I am Martina Di Rita, a PhD student at Geodesy and Geomatics Division, "Sapienza" University of Rome. I have developed a PlugIn to OSSIM for DSM generation from an optical stereo-pair in the framework of the last Google Summer of Code.

I have seen that OSGeo is a GSoC mentoring organization also this year, that's great!

I have checked the OSGeo GSoC wiki page and I have seen that so far there are no OSSIM ideas in... there is some reason? Is OSSIM involved this year in the GSoC?

I would like to propose a project for improve and develop the PlugIn I have created for the last GSoC.

My idea was to improve and edit where necessary the PlugIn for DSM generation (I have named it DATE - Digital Automatic Terrain Extractor) and, starting from what I have already done, extend it and enable it to process also a triplet and not only a stereo-pair (since we are witnessing a quick increase of tri-stereo satellite sensors). Furthermore I would like also to include the possibility to use SAR imagery for DSM stereo reconstruction (i.e. radargrammetry) in addition to the "optical option" already developed.
Finally, I would love to be able to "plug" the PlugIn in the OSSIM library in order to make it actually available for everyone.

Let me know what do you think about.

Kind regards,

Martina Di Rita

--
Martina Di Rita, PhD Student                               
Geodesy and Geomatics Division   
University of Rome "La Sapienza"
via Eudossiana, 18 - 00184 Rome Italy

Phone <a href="tel:%2B%2B39%200644585087" value="&#43;390644585087" target="_blank">++39 0644585087
E-mail martina.dirita@...

------------------------------------------------------------------------------
Dive into the World of Parallel Programming The Go Parallel Website, sponsored
by Intel and developed in partnership with Slashdot Media, is your hub for all
things parallel software development, from weekly thought leadership blogs to
news, videos, case studies, tutorials and more. Take a look and join the
conversation now. http://goparallel.sourceforge.net/
_______________________________________________
www.ossim.org
Ossim-developer mailing list
[hidden email]
https://lists.sourceforge.net/lists/listinfo/ossim-developer

------------------------------------------------------------------------------
Dive into the World of Parallel Programming The Go Parallel Website, sponsored
by Intel and developed in partnership with Slashdot Media, is your hub for all
things parallel software development, from weekly thought leadership blogs to
news, videos, case studies, tutorials and more. Take a look and join the
conversation now. http://goparallel.sourceforge.net/
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Re: GSoC 2015_OSSIM project

Martina Di Rita
Dear Mark,

If you think it could be a good idea, I can start writing a draft proposal and afterwards I can share it with the OSSIM community for comments and suggestions.

Thank you for your support.

Regards,

Martina

2015-03-14 12:49 GMT+01:00 Lucas, Mark <[hidden email]>:

Martina

We would be happy to work with you on this.
I am currently returning from foss4gna 
Let me know what you need

Mark
Sent from my iPhone

On Mar 13, 2015, at 10:00 AM, Martina Di Rita <[hidden email]> wrote:

Dear OSSIM dev community,

I am Martina Di Rita, a PhD student at Geodesy and Geomatics Division, "Sapienza" University of Rome. I have developed a PlugIn to OSSIM for DSM generation from an optical stereo-pair in the framework of the last Google Summer of Code.

I have seen that OSGeo is a GSoC mentoring organization also this year, that's great!

I have checked the OSGeo GSoC wiki page and I have seen that so far there are no OSSIM ideas in... there is some reason? Is OSSIM involved this year in the GSoC?

I would like to propose a project for improve and develop the PlugIn I have created for the last GSoC.

My idea was to improve and edit where necessary the PlugIn for DSM generation (I have named it DATE - Digital Automatic Terrain Extractor) and, starting from what I have already done, extend it and enable it to process also a triplet and not only a stereo-pair (since we are witnessing a quick increase of tri-stereo satellite sensors). Furthermore I would like also to include the possibility to use SAR imagery for DSM stereo reconstruction (i.e. radargrammetry) in addition to the "optical option" already developed.
Finally, I would love to be able to "plug" the PlugIn in the OSSIM library in order to make it actually available for everyone.

Let me know what do you think about.

Kind regards,

Martina Di Rita

--
Martina Di Rita, PhD Student                               
Geodesy and Geomatics Division   
University of Rome "La Sapienza"
via Eudossiana, 18 - 00184 Rome Italy

Phone <a href="tel:%2B%2B39%200644585087" value="+390644585087" target="_blank">++39 0644585087
E-mail martina.dirita@...

------------------------------------------------------------------------------
Dive into the World of Parallel Programming The Go Parallel Website, sponsored
by Intel and developed in partnership with Slashdot Media, is your hub for all
things parallel software development, from weekly thought leadership blogs to
news, videos, case studies, tutorials and more. Take a look and join the
conversation now. http://goparallel.sourceforge.net/
_______________________________________________
www.ossim.org
Ossim-developer mailing list
[hidden email]
https://lists.sourceforge.net/lists/listinfo/ossim-developer



--
Martina Di Rita, PhD Student                               
Geodesy and Geomatics Division   
University of Rome "La Sapienza"
via Eudossiana, 18 - 00184 Rome Italy

Phone <a href="tel:%2B%2B39%200644585087" value="+390644585087" target="_blank">++39 0644585087
E-mail martina.dirita@...

------------------------------------------------------------------------------
Dive into the World of Parallel Programming The Go Parallel Website, sponsored
by Intel and developed in partnership with Slashdot Media, is your hub for all
things parallel software development, from weekly thought leadership blogs to
news, videos, case studies, tutorials and more. Take a look and join the
conversation now. http://goparallel.sourceforge.net/
_______________________________________________
www.ossim.org
Ossim-developer mailing list
[hidden email]
https://lists.sourceforge.net/lists/listinfo/ossim-developer
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Re: GSoC 2015_OSSIM project

Mark Lucas-4
Martina, 
I think it would be a great idea to extend your terrain extraction for the OSSIM baseline.  We can provide technical support as we go through the next phase.  Let me know what you need as you go through the submittal process.

Mark


On Mar 16, 2015, at 7:49 AM, Martina Di Rita <[hidden email]> wrote:

Dear Mark,

If you think it could be a good idea, I can start writing a draft proposal and afterwards I can share it with the OSSIM community for comments and suggestions.

Thank you for your support.

Regards,

Martina

2015-03-14 12:49 GMT+01:00 Lucas, Mark <[hidden email]>:

Martina

We would be happy to work with you on this.
I am currently returning from foss4gna 
Let me know what you need

Mark
Sent from my iPhone

On Mar 13, 2015, at 10:00 AM, Martina Di Rita <[hidden email]> wrote:

Dear OSSIM dev community, 

I am Martina Di Rita, a PhD student at Geodesy and Geomatics Division, "Sapienza" University of Rome. I have developed a PlugIn to OSSIM for DSM generation from an optical stereo-pair in the framework of the last Google Summer of Code.

I have seen that OSGeo is a GSoC mentoring organization also this year, that's great!

I have checked the OSGeo GSoC wiki page and I have seen that so far there are no OSSIM ideas in... there is some reason? Is OSSIM involved this year in the GSoC?

I would like to propose a project for improve and develop the PlugIn I have created for the last GSoC.

My idea was to improve and edit where necessary the PlugIn for DSM generation (I have named it DATE - Digital Automatic Terrain Extractor) and, starting from what I have already done, extend it and enable it to process also a triplet and not only a stereo-pair (since we are witnessing a quick increase of tri-stereo satellite sensors). Furthermore I would like also to include the possibility to use SAR imagery for DSM stereo reconstruction (i.e. radargrammetry) in addition to the "optical option" already developed.
Finally, I would love to be able to "plug" the PlugIn in the OSSIM library in order to make it actually available for everyone.

Let me know what do you think about.

Kind regards, 

Martina Di Rita

-- 
Martina Di Rita, PhD Student                                
Geodesy and Geomatics Division    
University of Rome "La Sapienza" 
via Eudossiana, 18 - 00184 Rome Italy

Phone <a href="tel:%2B%2B39%200644585087" value="&#43;390644585087" target="_blank" class="">++39 0644585087
E-mail martina.dirita@...

------------------------------------------------------------------------------
Dive into the World of Parallel Programming The Go Parallel Website, sponsored
by Intel and developed in partnership with Slashdot Media, is your hub for all
things parallel software development, from weekly thought leadership blogs to
news, videos, case studies, tutorials and more. Take a look and join the 
conversation now. http://goparallel.sourceforge.net/
_______________________________________________
www.ossim.org
Ossim-developer mailing list
[hidden email]
https://lists.sourceforge.net/lists/listinfo/ossim-developer



-- 
Martina Di Rita, PhD Student                                
Geodesy and Geomatics Division    
University of Rome "La Sapienza" 
via Eudossiana, 18 - 00184 Rome Italy

Phone <a href="tel:%2B%2B39%200644585087" value="&#43;390644585087" target="_blank" class="">++39 0644585087
E-mail martina.dirita@...


------------------------------------------------------------------------------
Dive into the World of Parallel Programming The Go Parallel Website, sponsored
by Intel and developed in partnership with Slashdot Media, is your hub for all
things parallel software development, from weekly thought leadership blogs to
news, videos, case studies, tutorials and more. Take a look and join the
conversation now. http://goparallel.sourceforge.net/
_______________________________________________
www.ossim.org
Ossim-developer mailing list
[hidden email]
https://lists.sourceforge.net/lists/listinfo/ossim-developer
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Re: GSoC 2015_OSSIM project

Martina Di Rita
Dear Mark and OSSIM dev community,

hereinafter you can find the core of my GSoC proposal. I would be happy to have any comments or suggestions from you in order to improve the project and propose a good and useful new tool for OSSIM.


THE IDEA
Starting from what I have developed during the 2014 Google Summer of Code, the idea is to extend the OSSIM PlugIn in order
to manage triplet imagery (i.e. Pleiades, ZY3, etc.) for DSM generation. In particular adopting a multi-image matching technique
it is possible to reconstruct the scene using multiple disparity maps and to fuse them in order to obtain a more accurate depth image
by exploiting the redundancy of multiple disparity estimation.
Beside, I would like to further expand the PlugIn and include the possibility to also use SAR imagery for DSM stereo reconstruction
(i.e. radargrammetry) in addition to the optical workflow I have developed in the last GSoC.
As regards the DSM generation from a tristereo data set, the implementation flow that will be followed is very similar to the one
I have developed in the past GSoC, modified for managing a triplet. It is the subsequent:
a) Imagery preprocessing with a Wallis filter b) Imagery projection: the three images are projected in a ground geometry using a coarse DSM or a constant-height plane c) Automatic Tie Point (TP) identification with a subsequent filter to remove outliers, by using the nadiral image as a master for both
backward and forward images
d) Through the identified Tps, computation of the quasi-epipolar image geometry e) Disparity maps generation, using the Semi-Global-Block Matching (SGBM) algorithm implemented in the OpenCV library f) Disparity maps fusion and filtering g) DSM geocoding and interpolation over a regular ground grid a) In order to improve the TPs detection, I would like to preprocess the images implementing a Wallis filter to enhance the local
contrast throughout the image, while reducing the overall contrast between bright and dark areas. In this way the subsequent dense
matching will be more effective.


b) In general for high resolution images, non rigorous transformations based on RPF between object space and image space are used
to replace more rigorous sensor models where there is a confidentiality aspect, a need for generality or where greater speed is needed.
Within OSSIM the RPC orientation model is already managed by the ossimChipperUtil class and it could be conveniently adopted to
perform imagery projection using a coarse DSM or a constant-height plane.
c) In order to produce at least a pixel accurate quasi-epipolar images it is necessary a preliminary relative orientation model refinement
using a proper number of TPs collected between the images. For this purpose I would like to adopt the Orb detector and the Brief
descriptor implemented in the OpenCV library to detect automatically the corresponding features between the nadiral and respectively
the backward and the forward images.
d) Concerning the generation of the quasi-epipolar images, I can figure out to estimate a model transformation for make the input
images quasi-epipolar thanks to the identified TPs. What I want to do is to apply this transformation on both the backward and the
forward images with respect to the nadiral master in order to fix all the images on the same quasi-epipolar line.
e) As regards the disparity map creation from various images, this is derived from the offset between the same object in different
images. This will be done, once establishing corresponding matches between images, through the quasi-epiline constraint.
For this task I will employ the SGM algorithm, that is a monodimensional matching process that minimize the cost function along
the epipolar line in order to compute the disparity map. The OpenCV Class StereoSGBM (or the same class designed for exploit GPU
capabilities) is the most suitable tool for accomplishing this task, as I have already tested in developing DATE PlugIn, and it has been
widely used for satellite image 3D reconstruction. I will use this class for retrieving stereo correspondences: this is done browsing
throughout the epipolar line to compute cost aggregation in order to enforce a global smoothness constraint on the solution. The main
advantage of this matching technique is that without these constraints the disparity for each pixel would be computed without
consideration of the estimated disparity of its neighbours and the result would typically contain a lot of 'noise' as the process could
return many false positives.
f) The disparity maps created with the SGBM algorithm are fused together in order to obtain a more accurate depth image and recover
the 3D structure of the scene by exploiting the redundancy of multiple disparity estimation. Moreover it is possible to check the
quality of the matched points and to filter out the worst ones.
g) Finally, it is necessary to convert the fused disparity map obtained into a geocoded DSM. For every pixel of the disparity it is
possible to retrieve the height starting from the relative pixel shift and considering the stereo geometry.


As can be deduced, the major changes for implementing a tristereo DSM generation workflow with respect to the already developed
optical stereo DATE OSSIM PlugIn, lies at points a) and f) namely the preprocessing and the Disparity Maps fusion phases.

Regarding SAR imagery processing chain, the principal steps are almost the same already implemented in the DATE PlugIn, though
adapted for SAR images. It must be said that in this case the major changes are related to the orientation model and the preprocessing
phase: as a matter of fact it is fundamental to use a correct orientation model to perform a reliable ground reprojection in order to
reduce peculiar SAR geometrical distorsions that would be detrimental for an effective matching. In OSSIM the high resolution
SAR imagery orientation model is managed, amomg others, by the ossimTerraSarModel and ossimRadarSatModel sensor model.
Furthermore, I figure out to preprocess the images with one of the standard speckle filter used in the radar imaging community
(e.g. Lee, Kuan, GammaMap, etc.) for detection and classification optimisation with SAR imagery.


Feel free to let me know what you think.
Many thanks,

Martina

2015-03-16 13:32 GMT+01:00 Lucas, Mark <[hidden email]>:
Martina, 
I think it would be a great idea to extend your terrain extraction for the OSSIM baseline.  We can provide technical support as we go through the next phase.  Let me know what you need as you go through the submittal process.

Mark


On Mar 16, 2015, at 7:49 AM, Martina Di Rita <[hidden email]> wrote:

Dear Mark,

If you think it could be a good idea, I can start writing a draft proposal and afterwards I can share it with the OSSIM community for comments and suggestions.

Thank you for your support.

Regards,

Martina

2015-03-14 12:49 GMT+01:00 Lucas, Mark <[hidden email]>:

Martina

We would be happy to work with you on this.
I am currently returning from foss4gna 
Let me know what you need

Mark
Sent from my iPhone

On Mar 13, 2015, at 10:00 AM, Martina Di Rita <[hidden email]> wrote:

Dear OSSIM dev community, 

I am Martina Di Rita, a PhD student at Geodesy and Geomatics Division, "Sapienza" University of Rome. I have developed a PlugIn to OSSIM for DSM generation from an optical stereo-pair in the framework of the last Google Summer of Code.

I have seen that OSGeo is a GSoC mentoring organization also this year, that's great!

I have checked the OSGeo GSoC wiki page and I have seen that so far there are no OSSIM ideas in... there is some reason? Is OSSIM involved this year in the GSoC?

I would like to propose a project for improve and develop the PlugIn I have created for the last GSoC.

My idea was to improve and edit where necessary the PlugIn for DSM generation (I have named it DATE - Digital Automatic Terrain Extractor) and, starting from what I have already done, extend it and enable it to process also a triplet and not only a stereo-pair (since we are witnessing a quick increase of tri-stereo satellite sensors). Furthermore I would like also to include the possibility to use SAR imagery for DSM stereo reconstruction (i.e. radargrammetry) in addition to the "optical option" already developed.
Finally, I would love to be able to "plug" the PlugIn in the OSSIM library in order to make it actually available for everyone.

Let me know what do you think about.

Kind regards, 

Martina Di Rita

-- 
Martina Di Rita, PhD Student                                
Geodesy and Geomatics Division    
University of Rome "La Sapienza" 
via Eudossiana, 18 - 00184 Rome Italy

Phone <a href="tel:%2B%2B39%200644585087" value="+390644585087" target="_blank">++39 0644585087
E-mail martina.dirita@...

------------------------------------------------------------------------------
Dive into the World of Parallel Programming The Go Parallel Website, sponsored
by Intel and developed in partnership with Slashdot Media, is your hub for all
things parallel software development, from weekly thought leadership blogs to
news, videos, case studies, tutorials and more. Take a look and join the 
conversation now. http://goparallel.sourceforge.net/
_______________________________________________
www.ossim.org
Ossim-developer mailing list
[hidden email]
https://lists.sourceforge.net/lists/listinfo/ossim-developer



-- 
Martina Di Rita, PhD Student                                
Geodesy and Geomatics Division    
University of Rome "La Sapienza" 
via Eudossiana, 18 - 00184 Rome Italy

Phone <a href="tel:%2B%2B39%200644585087" value="+390644585087" target="_blank">++39 0644585087
E-mail martina.dirita@...




--
Martina Di Rita, PhD Student                               
Geodesy and Geomatics Division   
University of Rome "La Sapienza"
via Eudossiana, 18 - 00184 Rome Italy

Phone <a href="tel:%2B%2B39%200644585087" value="+390644585087" target="_blank">++39 0644585087
E-mail martina.dirita@...

------------------------------------------------------------------------------
Dive into the World of Parallel Programming The Go Parallel Website, sponsored
by Intel and developed in partnership with Slashdot Media, is your hub for all
things parallel software development, from weekly thought leadership blogs to
news, videos, case studies, tutorials and more. Take a look and join the
conversation now. http://goparallel.sourceforge.net/
_______________________________________________
www.ossim.org
Ossim-developer mailing list
[hidden email]
https://lists.sourceforge.net/lists/listinfo/ossim-developer