IPB

Welcome Guest ( Log In | Register )

6 Pages V   1 2 3 > »   
Reply to this topicStart new topic
High-Res DEMs from single HiRISE images, First results of new "Shape from Shading" algorithm
Nirgal
post Jan 16 2010, 03:30 PM
Post #1


Member
***

Group: Members
Posts: 713
Joined: 30-March 05
Member No.: 223



Hi all,

Here the long overdue continuation of the "Alien Landscapes" series. This time based on 3D
DEMs generated with "Shape from Shading" from single HiRISE images.
Enjoy smile.gif

Click on Images for larger version.

Detail views from PSP_002172_1410 (large gully system)





Detail view of Gullies from PSP_001376_1675





Detail of gully system in PSP_002022_1455



Dune Views from PSP_004339_1890





Detail from PSP_001834_1605





Here is some background info on the making of the images:

"Shape from Shading" (SFS) i.e. the possibility to extract shape information from a single image has always been a fascinating topic for me.
Now I found the time to implement a prototype for a new SFS algorithm based on some ideas that I've been thinking about for a long time.
The problem with existing SFS approaches (see here for a survey is that they either tend to over-smooth the details (due to the regularization constraint) or suffer from excessive noise in the high-frequency components of the reconstructed surface. Another problem is the large demand on CPU ressources which would make them very challenging to apply to large scale input data, such as HiRISE orbiter images.

So for a long time I was rather sceptical as to the potential of SFS and it was my impression that Methods based on multiple images (stereo) must be far superior to single-image SFS.

However, after a long time of experimenting, combining existing approaches with some new ideas, I got the following quite promising first results that I'd like to share:

All of the images were generated from a single HiRISE image (no depth information was used from stereo or laser altimeter data).
Also, no texturing or additional coloring/shading was applied when rendering the surface.
Every detail visible is real 3D down to the pixel-level...
For rendering I used a very simple model based on lambertian reflection with gouraud shading.

The resolution of the images is still moderate: that is downsampled details crops in the order of 0.5-1 Megapixels.
However, despite the heavy math machinery that drives the core of the algoritm (several systems of equations with millions of unknowns)
the processing time is still moderate (about 15 Minutes per med-res image, using about 2 Gigs main mem) such that the application to full-res HiRISE images should be possible smile.gif

The following image shows an example to illustrate the general principle (click to enlarge).


On the left hand side the 2D input image (simple noisy JPEG from the Web with unknwon light source direction). On the right hand side shows the recovered 3D surface re-lighted under a different light source direction.
Note that one problem of the current implementation of the algorithm is it's vulnerability to notable distortions in the low frequency components (i.e. large scale variations) of the generated surface. However I'm confident that this can be overcome by an improved version or by adding the large-scale depth information from stereo-based DEMs or altimeter data (MOLA) where available.
Go to the top of the page
 
+Quote Post
lyford
post Jan 16 2010, 04:29 PM
Post #2


Senior Member
****

Group: Members
Posts: 1264
Joined: 18-December 04
From: San Diego, CA
Member No.: 124



WOAH! blink.gif

I want to climb those dunes..... amazing!


--------------------
Lyford Rome
"Zis is not nuts, zis is super-nuts!" Mathematician Richard Courant on viewing an Orion test
Go to the top of the page
 
+Quote Post
mhoward
post Jan 16 2010, 05:03 PM
Post #3


Senior Member
****

Group: Moderator
Posts: 3426
Joined: 11-August 04
From: USA
Member No.: 98



Mind-blowing. ohmy.gif
Go to the top of the page
 
+Quote Post
cbcnasa
post Jan 16 2010, 05:48 PM
Post #4


Junior Member
**

Group: Members
Posts: 57
Joined: 22-March 09
From: West Hartford, Connecicut
Member No.: 4691



The images are just amazing, fantastic job.
Go to the top of the page
 
+Quote Post
jamescanvin
post Jan 16 2010, 06:05 PM
Post #5


Senior Member
****

Group: Moderator
Posts: 2184
Joined: 9-February 04
From: UK
Member No.: 16



Those are just astonishing Bernhard, great work! ohmy.gif


--------------------
Go to the top of the page
 
+Quote Post
ElkGroveDan
post Jan 16 2010, 06:39 PM
Post #6


Senior Member
****

Group: Admin
Posts: 4663
Joined: 15-March 05
From: Sloughhouse, CA
Member No.: 197



Amazing and beautiful stuff, as always. I don't know about everyone else but my mind is spinning as I ponder the implications of this process. I can see demand for a self-contained software product for this process, or at least a plug-in for one of the popular 3-D utilities.


--------------------
If Occam had heard my theory, things would be very different now.
Go to the top of the page
 
+Quote Post
eoincampbell
post Jan 16 2010, 07:13 PM
Post #7


Member
***

Group: Members
Posts: 392
Joined: 28-August 07
From: San Francisco
Member No.: 3511



Another UMSF classic, it's truly a joy to come here and view this wonderful work,
thanks for posting that...


--------------------
'She drove until the wheels fell off...'
Go to the top of the page
 
+Quote Post
PDP8E
post Jan 16 2010, 07:43 PM
Post #8


Member
***

Group: Members
Posts: 529
Joined: 10-October 06
From: Maynard Mass USA
Member No.: 1241



Bernhard,
This is fabulous progress report!
I hope to see you write this up in a journal soon. The images are stunning
(I look forward to the day I can use your technique!) Cheers


--------------------
CLA CLL
Go to the top of the page
 
+Quote Post
djellison
post Jan 16 2010, 08:20 PM
Post #9


Administrator
****

Group: Chairman
Posts: 13870
Joined: 8-February 04
Member No.: 1



O

M

F

G
Go to the top of the page
 
+Quote Post
Tesheiner
post Jan 16 2010, 08:36 PM
Post #10


Senior Member
****

Group: Moderator
Posts: 4275
Joined: 19-April 05
From: .br at .es
Member No.: 253



Unbelievable!!! blink.gif
I want to climb one of those hills.
Go to the top of the page
 
+Quote Post
Bjorn Jonsson
post Jan 16 2010, 09:09 PM
Post #11


IMG to PNG GOD
****

Group: Moderator
Posts: 1529
Joined: 19-February 04
From: Near fire and ice
Member No.: 38



In a word:

WOW!!!

Are you draping the original image over the DEM or is the DEM itself this detailed?
Go to the top of the page
 
+Quote Post
Reckless
post Jan 16 2010, 09:25 PM
Post #12


Member
***

Group: Members
Posts: 221
Joined: 25-March 05
Member No.: 217



Brilliant Bernhard

As I was looking at those pictures I was wondering what Doug would think of them... then he posted.
Nuff said.

Roy
Go to the top of the page
 
+Quote Post
nprev
post Jan 16 2010, 09:32 PM
Post #13


Senior Member
****

Group: Moderator
Posts: 7178
Joined: 8-December 05
From: Los Angeles
Member No.: 602



Just freakin' amazing, is all! What immediacy these images have.


--------------------
A few will take this knowledge and use this power of a dream realized as a force for change, an impetus for further discovery to make less ancient dreams real.
Go to the top of the page
 
+Quote Post
Nirgal
post Jan 16 2010, 10:27 PM
Post #14


Member
***

Group: Members
Posts: 713
Joined: 30-March 05
Member No.: 223



QUOTE (Bjorn Jonsson @ Jan 16 2010, 10:09 PM) *
In a word:

WOW!!!

Are you draping the original image over the DEM or is the DEM itself this detailed?


There is no texture mapping or smoothing involved: every pixel is real 3D - The DEM itself is detailed down to the single pixel level.

That's the really interesting thing with this new techinque: The absence of the strong smoothing process that gives many conventional DEM-images that somewhat "washed", unnaturally soft appearance. smile.gif

(however: while it works perfectly for the higher frequency bands, there can be distortions in the lower frequency components ...
so the DEMs in their current form could probably not be used for exact inference about variations of absolute terrain heights over larger scales (that's where MOLA and conventional stereo based techniques have advantages: so it seems natural to combine the techniques) ...

P.S.: I also forgot to mention that in most images the vertical scale is exaggerated by a factor of about 1.5 to 2.
Go to the top of the page
 
+Quote Post
Stu
post Jan 16 2010, 10:29 PM
Post #15


The Poet Dude
****

Group: Moderator
Posts: 5548
Joined: 15-March 04
From: Kendal, Cumbria, UK
Member No.: 60



QUOTE (Nirgal @ Jan 16 2010, 10:27 PM) *
P.S.: I also forgot to mention that in most images the vertical scale is exaggerated by a factor of about 1.5 to 2.


Can your amazing new process create renders with no vertical exaggeration? I'd love to see those! smile.gif


--------------------
Go to the top of the page
 
+Quote Post

6 Pages V   1 2 3 > » 
Reply to this topicStart new topic

 



RSS Lo-Fi Version Time is now: 22nd December 2014 - 12:01 PM
RULES AND GUIDELINES
Please read the Forum Rules and Guidelines before posting.

IMAGE COPYRIGHT
Images posted on UnmannedSpaceflight.com may be copyrighted. Do not reproduce without permission. Read here for further information on space images and copyright.

OPINIONS AND MODERATION
Opinions expressed on UnmannedSpaceflight.com are those of the individual posters and do not necessarily reflect the opinions of UnmannedSpaceflight.com or The Planetary Society. The all-volunteer UnmannedSpaceflight.com moderation team is wholly independent of The Planetary Society. The Planetary Society has no influence over decisions made by the UnmannedSpaceflight.com moderators.
SUPPORT THE FORUM
Unmannedspaceflight.com is a project of the Planetary Society and is funded by donations from visitors and members. Help keep this forum up and running by contributing here.