Topics

1

General / Question regarding pixel size

« on: June 25, 2015, 06:21:24 PM »

Hello community,

in the camera calibration settings, I can set the pixel size (mm). I have two questions regarding this vaule:
1. Which pixel size is of interest? Many cameras have a higher density of pixels on their actual sensors than the resulting pictures will have (effevtive vs. total). Which value should be used?
2. At which point in the calculation is this value used? What does it change, when adding the value in the end? Which steps need to be redone?

Best regards.

2

Bug Reports / Circles in DEM

« on: March 26, 2015, 04:02:44 PM »

Hello.

I am using PhotoScan to generate a Digital Elevation Model. I have almost 60 pictues, taken from a UAV platform, the coverage ist pretty well and I get a final result with a ground resolution of 2,2 cm.

I chose the following setting:
- Build Dense Cloud: Very high
- Build Mesh: highest Option; no interpolation
- Export DEM: suggested resolution (2,2cm)

The DEM looks normal, but when I use the DEM to calculate a shaded relief in ArcGIS, I can see many circles in some areas. They definitely come from the PhotoScan-model. My first idea was, that they might be because of the interpolation during mesh building, but even if turned off, they are still there. I tried several other options (resolution, quality-settings), but the result always shows these circles (see attached picture).

Any ideas where this is coming from, if it is a bug or something I can avoid?

Thanks,
fsteiner