Messages

1

General / Ground control points for aerial survey

« on: May 06, 2014, 12:31:32 PM »

Hi,

I like to do an aerial survey from about 100 to 200 m altitude and I am looking for a solution for the ground control points.

Ideally the points should have the following requirements:
- good visibility
- easy to transport
- light weight
- fixed to the ground (no flying away by wind)
- low cost
- if possible: decomposable, so I do not have to pick the points up after the survey 

Until now I used paper plates, but they are hard to fix to the ground and are prone to rain and hungry sheep.
Any recommendations?

2

General / Re: Photomast?

« on: April 29, 2014, 03:53:52 AM »

I used selfmade poles for taking photos in archaeological contexts.

For vertical shoots I am using a telescopic window cleaning pole or a photo crane. You can read about it here: https://www.academia.edu/3589584/Structure-from-Motion_und_Pole-Aerial-Photography_fur_die_Dokumentation_archaologischer_Grabungen (in german but with pictures)


For horizontal pictures of walls and facades I am using a fishing rod that can be used up to 13 m with a point-and-shoot camera. See image attached.

3

General / DEM (Geotiff) - coordinate systems (solved)

« on: April 24, 2014, 07:40:44 PM »

Hello,

I would like to visualize exported elevation models from photoscan within a software (http://iaps.zrc-sazu.si/en/svf#v RVT standalone version 1.0). However, it does not work because the geotiffs generated by Photoscan seem to have a strange coordinate system. It does not matter if I use local coordinates or a projected coordinate system, the RVT toolbox says that the input DEM is given in geographic coordinates. I already mailed with the developers of the toolbox and they told me to check photoscan for the units of the exported DEM.
Any help is appreciated.

Ronald

Edit: Problem solved, my model had too high resolution for the software used.

 

4

General / Re: advice about using Canon S100 for UAV maping

« on: January 30, 2014, 02:22:51 PM »

Hi Charly,

there is a very usefull script for Canon cameras: http://chdk.wikia.com/wiki/KAP_%26_UAV_Exposure_Control_Script

Using it on a kite and pole I end up with much more useable photographs than in auto mode.

When using the Canon you should take photos in RAW format. It gives better (more accurate model, better texture) results than the jpg that are automatically lens distortion corrected, which is what PhotoScan can do better I think.

Best
Ronald

5

General / Re: Agisoft PhotoScan 1.0.0 pre-release

« on: December 01, 2013, 11:30:00 PM »

Hello Ronald,

Could you please try build 1774, we have fixed some issues for orthophoto export there that may have appeared for complex objects (at the second issue should be fixed).

The strange colours still occur in build 1774 while exporting orthophoto using colour correction. It does not happen without colour correction. I checked my images and it seems to be some kind of footprint (better the shadow of a footprint) of some low exposed pictures. I am sorry I don`t have a log file.

Another bug I just experienced in build 1780 is the change image path command. It does not work properly. Changing image path will change the path if you check for the image path of the pictures but if you want to allign the chunk again it says images are missing and directs to the previous path. After saving the job and re-open photoscan the pathes are changed back to the previous pathes again. Forget about it....now it works...

6

General / Re: Agisoft PhotoScan 1.0.0 pre-release

« on: November 25, 2013, 12:14:00 AM »

Hi Alexey,

the export is from build 1771.
No, there were no blue images. The textured model itself (generic, mosaic 16384x1 texture size, colour correction enabled) looks great! However, if I export the orthophote in default settings (mosaic) I get this strange result. So far I was not able to reproduce it since orthophoto export took me 12 hours (around 1200 photos used).

Also, the orthophoto partly shows textures that are on the back of the building. Will try to disable all cameras I don`t need for texture building, build texture again and then try to export orthophoto with diabled cameras from backside.

7

General / Re: Agisoft PhotoScan 1.0.0 pre-release

« on: November 24, 2013, 11:36:35 PM »

Hi,

I exported an orthopho from a model and got a strange result. Seems like the texture given by some cameras is not calculated correctly. See image attached.