High-Res DEMs from single HiRISE images, First results of new "Shape from Shading" algorithm |
High-Res DEMs from single HiRISE images, First results of new "Shape from Shading" algorithm |
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 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 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. |
|
|
Jan 16 2010, 04:29 PM
Post
#2
|
|
Senior Member Group: Members Posts: 1281 Joined: 18-December 04 From: San Diego, CA Member No.: 124 |
WOAH!
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 |
|
|
Jan 16 2010, 05:03 PM
Post
#3
|
|
Senior Member Group: Moderator Posts: 3431 Joined: 11-August 04 From: USA Member No.: 98 |
Mind-blowing.
|
|
|
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.
|
|
|
Jan 16 2010, 06:05 PM
Post
#5
|
|
Senior Member Group: Moderator Posts: 2262 Joined: 9-February 04 From: Melbourne - Oz Member No.: 16 |
Those are just astonishing Bernhard, great work!
-------------------- |
|
|
Jan 16 2010, 06:39 PM
Post
#6
|
|
Senior Member Group: Admin Posts: 4763 Joined: 15-March 05 From: Glendale, AZ 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.
|
|
|
Jan 16 2010, 07:13 PM
Post
#7
|
|
Member Group: Members Posts: 399 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...'
|
|
|
Jan 16 2010, 07:43 PM
Post
#8
|
|
Member Group: Members Posts: 808 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
|
|
|
Jan 16 2010, 08:20 PM
Post
#9
|
|
Founder Group: Chairman Posts: 14433 Joined: 8-February 04 Member No.: 1 |
O
M F G |
|
|
Jan 16 2010, 08:36 PM
Post
#10
|
|
Senior Member Group: Moderator Posts: 4279 Joined: 19-April 05 From: .br at .es Member No.: 253 |
Unbelievable!!!
I want to climb one of those hills. |
|
|
Jan 16 2010, 09:09 PM
Post
#11
|
|
IMG to PNG GOD Group: Moderator Posts: 2251 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? |
|
|
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 |
|
|
Jan 16 2010, 09:32 PM
Post
#13
|
|
Merciless Robot Group: Admin Posts: 8784 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.
|
|
|
Jan 16 2010, 10:27 PM
Post
#14
|
|
Member Group: Members Posts: 713 Joined: 30-March 05 Member No.: 223 |
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. (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. |
|
|
Jan 16 2010, 10:29 PM
Post
#15
|
|
The Poet Dude Group: Moderator Posts: 5551 Joined: 15-March 04 From: Kendal, Cumbria, UK Member No.: 60 |
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! -------------------- |
|
|
Lo-Fi Version | Time is now: 5th June 2024 - 07:36 AM |
RULES AND GUIDELINES Please read the Forum Rules and Guidelines before posting. IMAGE 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 funded by the Planetary Society. Please consider supporting our work and many other projects by donating to the Society or becoming a member. |