Messages

91

General / A few pink rectangles among the large number of blue rectangles

« on: January 30, 2017, 05:50:22 AM »

In my model view of cameras, there are several isolated pink rectangles?
What are these, and do I need to do something with them?

92

General / Re: Best way to process 4500 photos?

« on: January 30, 2017, 05:08:46 AM »

With that much RAM, why would you need more than one chunk?

93

General / Photo rotation needed or not?

« on: January 30, 2017, 04:30:39 AM »

I have a question about rotation of photos for aerial surveys.
This project has many photo sequences, mostly taken in a north-to-south, or south-to-north direction.  I rotated many of these in an external program, to make it easier for me to find GCPs which occur on existing orthophotos. The 'Align Photos' using Reference (photos had GPS in EXIF) worked well; but while placing GCPs, I have found some photos that I failed to rotate 180º, and I have some markers that are wanting to go in a completely wrong position.

What to do next? Ignore the marker for those photos? Rotate the images outside of Photoscan? Rotate them inside Photoscan? Does this mean my Key Point and Tie Point recognition needs to be repeated?

94

General / Re: Aerial photos with GPS, GCPs, limited RAM

« on: January 27, 2017, 05:16:46 AM »

Thank you for that, Alexey.

In the following message, you mention a script for creating a grid of bounding boxes. Could I get this script please?
www.agisoft.com/forum/index.php?topic=778.msg16285#msg16285

95

General / Re: Aerial photos with GPS, GCPs, limited RAM

« on: January 27, 2017, 12:27:24 AM »

Option 2. was mentioned by Alexey Pasumansky here www.agisoft.com/forum/index.php?topic=2672.msg14160#msg14160

Does anyone know is this is the best of the two options when RAM is limited?

96

General / Aerial photos with GPS, GCPs, limited RAM

« on: January 25, 2017, 01:25:08 AM »

I have looked at many posts, but it isn't obvious what approach to take.

I have about 4000 20MP photos (with GPS) to make into a high quality orthophoto (split into tiles).
I have 16GB of RAM, which I calculate is good for 600 photos at once.
I will use as many very accurate GCPs as required. Either 10 per chunk, or perhaps 20+ over the whole area.

How do I proceed? I see two choices.
Option 1: - process this as a series of overlapping chunks?
Option 2: - align all photos into one chunk using Reference preselection. I see mention of "duplicate the original chunk and generate mesh model for smaller areas by resizing the bounding box"

Any suggestions?

97

General / Re: Markers appearing on wrong photos

« on: January 19, 2017, 05:10:38 AM »

I know I shouldn't really reply to my own post, but I have somehow resolved the problem of markers appearing in absurdly wrong places. I did drop some photos. I did delete all my GCPs and re-import them, but still had a problem. Then today I re-opened the project and all was fine! Go figure!

98

General / Markers appearing on wrong photos

« on: January 17, 2017, 02:51:02 AM »

I have 14 ground control points for a set of 21 overlapping aerial photos.
After I have found and adjusted 3 markers on several photos, I Update & Optimize Cameras. Then I continue with remaining markers. Some markers are correct on one photo, but also appear a very long way away on a wrong photo.

How do I deal with markers which appear on a wrong photo? I want to keep the marker if it is on a correct photo.
- Do I just drag it off the photo, turning it from grey to a blue flag?

Also some unrelated questions:
- Is it important to include the pixel size in the Camera Calibration for a digital photo?
- When should I tick the Fixed calibration box?

99

General / Add/remove photos after GCP points all done?

« on: July 21, 2016, 01:28:35 AM »

I have 38 aerial photos in my project.
I have located and marked GCPs on all the photos.

I should have checked the photo quality earlier, and now want to remove 4 photos and replace them with some spare photos. Can I do this without re-observing all my GSPs?

100

General / Exclude trees from DTM

« on: July 20, 2016, 02:23:37 AM »

I'm new to PhotoScan, and am having trouble removing trees from my Dense Cloud.
- I have tried automatic, but aren't sure of the best values to use.
- I have tried manual, but the Mesh and DEM seem to be including All Points. (I selected a clump of trees and assigned them to Tree Class. Then I build the mesh using just the other points, but I think it is using all points.)
What step have I missed?