Forum

Author Topic: Agisoft PhotoScan 0.8.4 pre-release  (Read 31685 times)

RHenriques

  • Full Member
  • ***
  • Posts: 225
    • View Profile
Re: Agisoft PhotoScan 0.8.4 pre-release
« Reply #15 on: November 10, 2011, 01:01:39 AM »
The license key issue under Lion is gone, as Jan already posted.
Some work must be done in the orthophoto generation. This is a very sensitive issue for me because I work with UAV's for good orthophoto and DEM generation. Often some portions of the ortho get highly distorted, which it's more noticed in things that are geometrically well defined such as houses or straight roads. I never get the exactly same result while testing the same array of photos twice. Results are very good for the 3D terrain model, which tends to be very accurate, but are surprisingly and unexpectadly jagged in the orthophoto. The latest 1289 Beta produced better results in some parts of orthos i've made (Mosaic parameter) than in the latest betas but introduced some strange ghosting blurs around some well defined terrain features and abrupt rectilinear color transitions. I hope you can fine-tune this algorithm. I've made a test with the imagery from Sensefly site and results from Photoscan were better (when compared to the included post flight service) in the DEM generation. Posflight services from Sensefly produced a better Orthophoto. Even so, Photoscan can already achieve great results. Ortho from Sensefly is here "http://www.sensefly.com/downloads/mapping_examples/shoreline/tiles/googlemaps.html" and original RAW imagery, that can be tested in Photoscan, is available here "http://www.sensefly.com/downloads/mapping_examples/shoreline"
Cheers

Monserrat

  • Newbie
  • *
  • Posts: 18
    • View Profile
Re: Agisoft PhotoScan 0.8.4 pre-release
« Reply #16 on: November 10, 2011, 04:08:08 PM »
Hi RHenriques,

Are comparing two very different things, The service you are referring to use software SOCET SET  and Orima triangulation. (Bundle block adjustment). Those matching points and approximate values of the image position & orientation are used in a bundle block adjustment to reconstruct the exact position and orientation of the camera for every acquired image. This is the perfect input for photogrametry software such as Socet set and ERDAS.

If you want precision photogrammetry results, I recommend you then use precision photogrammetry tools.

Dmitry Semyonov

  • Agisoft Technical Support
  • Full Member
  • *****
  • Posts: 200
    • View Profile
Re: Agisoft PhotoScan 0.8.4 pre-release
« Reply #17 on: November 10, 2011, 06:30:51 PM »
Hello RHenriques,

Thank you for your comments.

Are you talking about visible shade changes across the photo boundaries? I have attached a preview of orthophoto we have just obtained from Shoreline data set.

I think that they can be decreased further, we should check this.
With best regards,
Dmitry Semyonov
Agisoft

RHenriques

  • Full Member
  • ***
  • Posts: 225
    • View Profile
Re: Agisoft PhotoScan 0.8.4 pre-release
« Reply #18 on: November 11, 2011, 01:24:05 AM »
Hi Dmitry, I noticed some distortion in the houses, the small harbour (the one with the blue boat) limits are also irregular. The shades that you are referring are also noticeable but not my main concern. The main problem is occasional distortion in random parts of the orthophoto. I cannot see your ortho perfectly (the file is too small) to see if you get the same problems as I did. For example, it seems that the house with the gray roof seems to be distorted in your photo, in the right side, which does not seem to occur in the SenseFly final result. This kind of distortions are my main problem with Photoscan now. It's strange because, most of the times, the limit of the 3D object in the DEM it's very accurate but the correspondant orthophoto limits are not.
Cheers

Hi Monserrat, are you sure about SenseFly service using Orima? Their service is this one http://pix4d.com/
I think that the software approach is very similar to the Photoscan one but I can be wrong, of course :-). The IMU unit from the SenseFly CAM UAV is not as precise as a real IMU unit from classic aerial photography. Mainly is used for the UAV navigation, stabilization and slightly for coarse photo alignment. Even the camera in the UAV is a consumer one. See their site for details. I doubt that it can be used with the workflow you described, common in classical photogrammetry. The reason I bought Photoscan is that I can get great results with a lot less work from images from these UAVS and from Kite aerial photography for instance. Even using classical aerial photography (1/15000 to 1/8000 scales), I've perfected a workflow, using Photoscan in the end, with photos digitized with a Photogrammetric Scanner (or even with photos from Digital Aerial Photography systems like an Intergraph DMC). The results are a lot better, more accurate and, mainly, much much less time consuming that I ever reached with ERDAS. For my investigation purposes, the results are perfectly within the precision that I could expect from this kind of photography. Of course, I always use a very accurate assemblage of ground control points obtained in the field, with precise geodesy data and a very precise Trimble GPS. This is the only way you can get satisfactory data from photogrammetry.

Cheers
« Last Edit: November 11, 2011, 01:29:48 AM by RHenriques »

Monserrat

  • Newbie
  • *
  • Posts: 18
    • View Profile
Re: Agisoft PhotoScan 0.8.4 pre-release
« Reply #19 on: November 24, 2011, 08:04:23 PM »
Hi RHenriques ,

For all who like to play with photogrammetry lite

http://www.123dapp.com/catch

RHenriques

  • Full Member
  • ***
  • Posts: 225
    • View Profile
Re: Agisoft PhotoScan 0.8.4 pre-release
« Reply #20 on: November 25, 2011, 12:47:24 AM »
Hi Monserrat
Thanks for the link :-)
I'm already using it to for educational purposes. I was using it before with the Photoscene name. They changed it to 123Dapp recently. My students are learning the principles and results of photogrammetry with it. It's not as powerful as Photoscan but we can achieve great results also. I noticed that, with large photo sets, photoscan produces better results. And of course, Photoscan deals with Orthos and Georreferencing.
Cheers :-)

wj

  • Newbie
  • *
  • Posts: 19
    • View Profile
Re: Agisoft PhotoScan 0.8.4 pre-release
« Reply #21 on: December 21, 2011, 04:43:40 AM »
Long time no update :-\ When it will be updated?Whether there will be anti-selection?
« Last Edit: December 21, 2011, 04:46:42 AM by wj »

Alexey Pasumansky

  • Agisoft Technical Support
  • Hero Member
  • *****
  • Posts: 14753
    • View Profile
Re: Agisoft PhotoScan 0.8.4 pre-release
« Reply #22 on: December 21, 2011, 11:21:55 AM »
Hello wj,

We are working on improvement of the align photos stage and it requires additional testing before releasing.
« Last Edit: December 21, 2011, 01:57:48 PM by Alexey Pasumansky »
Best regards,
Alexey Pasumansky,
Agisoft LLC

FoodMan

  • Sr. Member
  • ****
  • Posts: 477
    • View Profile
Re: Agisoft PhotoScan 0.8.4 pre-release
« Reply #23 on: December 22, 2011, 04:04:59 PM »
Hello wj,

We are working on improvement of the align photos stage and it requires additional testing before releasing.

cool.. ! 8)

h/

wj

  • Newbie
  • *
  • Posts: 19
    • View Profile
Re: Agisoft PhotoScan 0.8.4 pre-release
« Reply #24 on: December 22, 2011, 08:07:25 PM »
I think that the software need to improve the clarity of texture, the texture is not always clear and obscure. No matter what mode :)