Topics

1

Python and Java API / "Error: Empty extent" on chunk.buildOrthomosaic

« on: August 20, 2018, 08:47:35 PM »

For some reason I have "Error: Empty extent" on chunk.buildOrthomosaic.

What can be reason of such behaviour?

2

General / Is it possible to fix not aligned photos manually?

« on: August 14, 2018, 03:52:51 PM »

I have UAV flight and in some parts of it photos seems not aligned, so point cloud have holes in this part.
I have inspected this problem in Tools->Tie points->view matches and seems 'bad' photos have small number of matches about 800, other 'normal' photos have about 4k, I have tried to increase number of Key point limit and Tie point limit in in Align Photos settings but this don't help much.

What are possible reasons of such problems? How to fix this problem? maybe it's possible to fix not aligned photos manually?

3

General / Missing large parts from orthomosaic

« on: August 01, 2018, 02:56:32 PM »

I use following pipeline Sparse point cloud -> Mesh -> Orthomosaic, sparse point cloud and mesh look good, but in orthomosaic I have several large pieces that are missing, what can cause such problem? what can be done to overcome this problem?

4

General / Is it possible to crop area by region?

« on: July 13, 2018, 05:47:12 PM »

Is it possible to crop chunk point_cloud by region in GUI or python script?

5

Python and Java API / How to remove point cloud from chunk?

« on: July 13, 2018, 05:16:31 PM »

How to remove point cloud from chunk?

6

General / Holes on orthophoto with Enable hole filling when build from DEM

« on: July 11, 2018, 04:41:50 PM »

I get holes on orthophoto with Enable hole filling when build from DEM.

On DEM I can see that these areas are filled.

When building from mesh with Enable hole filling I still get holes, but they are smaller.

Is it normal behaviour?

Update:

Look like hole was with 1e-7 pixel size and with 1e-6 holes are gone, but I get another artifact DEM area is not the same as ortho area on borders. And I can't see the  pixel size setting for DEM is there any option to make it the same size as ortho?

7

Python and Java API / What is RasterFormatNone stand for?

« on: July 10, 2018, 04:31:34 PM »

I want to export orthomap not in tiled format.

I wast thinking that RasterFormatNone will help me to do this, but I get error that it's not supported : RuntimeError: Unsupported raster format

Code: [Select]

chunk.exportOrthomosaic(path, dx=1e-07, dy=1e-07, format=PhotoScan.RasterFormat.RasterFormatNone, image_format=PhotoScan.ImageFormat.ImageFormatTIFF, tiff_overviews=False, white_background=False, write_kml=True)

8

Python and Java API / Number of points in points cloud

« on: July 04, 2018, 04:09:24 PM »

As I can see len(chunk.point_cloud.points) gives me 79429 points, but when I use right click on project -> show info it show me 79429 of 103995, so as I understand chunk.point_cloud.points is just valid points? How can I access all points?

9

General / OOM at the end of export orthomosaic

« on: June 28, 2018, 07:47:48 PM »

I'm trying to export orthomosaic of large project, but get OOM(out-of-memory) at the end of export orthomosaic, as I can see memory consumption start grow drastically when 99% is done. I'm able successfully build orthomosaic from mesh builded from sparse point cloud and I'm export it in Google Map Tiles format.

If I can fit images and orthomap in memory why it crashes with OOM at export orthomosaic? as i understand it should just cut orthomosaic in tiles.

Is it a bug? If it matters after crash .zip file with tiles is about 20Gb and it's broken.

Also maybe someone can give additional recomendations for pipeline how to export orthomap in Google Map Tiles format with lowest memory consumption?

10

Python and Java API / What is track_id?

« on: June 18, 2018, 12:48:03 PM »

In docs I can see only:
track_id Track index in PointCloud.Point and PointCloud.Projection
http://www.agisoft.com/pdf/photoscan_python_api_1_4_2.pdf

Is it just unique indentificator of point or is it related to some consept of 'track'?

Also what is meant by `Point valid flag`?

11

General / How to limit number of cpus used by Photoscan?

« on: June 18, 2018, 12:42:01 PM »

How to limit number of cpus used by Photoscan?

12

General / Reproducibility of results

« on: May 30, 2018, 09:22:42 PM »

Can I get fully reproducible results in Photoscan? As I can see some procedure (maybe optimization) have some randomness, so can I fix random seed somehow to get fully reproducible report?

13

General / Aligh photos accuracy and error measured by gcp

« on: May 30, 2018, 03:06:12 PM »

As I can see in Alignment parameters section in Photoscan manual
http://www.agisoft.com/pdf/photoscan-pro_1_4_en.pdf

Accuracy
Accuracy
Higher  accuracy  settings  help  to  obtain  more  accurate  camera  position  estimates.  Lower  accuracy
settings can be used to get the rough camera positions in a shorter period of time.
While at High accuracy setting the software works with the photos of the original size, Medium setting
causes  image  downscaling  by  factor  of  4  (2  times  by  each  side),  at  Low  accuracy  source  files  are
downscaled by factor of 16, and Lowest value means further downscaling by 4 times more. Highest
accuracy  setting  upscales  the  image  by  factor  of  4.  Since  tie  point  positions  are  estimated  on  the
basis of feature spots found on the source images, it may be meaningful to upscale a source photo
to accurately localize a tie point. However, Highest accuracy setting is recommended only for very
sharp image data and mostly for research purposes due to the corresponding processing being quite
time consuming.

As I understand accuracy setting can be interpreted as image downsize factor:

Highest x2 up
High original size (?)
Medium x2 down
Low x4 down
Lowest x8 down (?)

Is it right?

Also when I measure accuracy of model by gcp points (that was not included in alighnment process) I expect that higher accuracy will give smaller error, but seems dependense is not linear and at lowest setting I get smallest error and that is weird, can someone confirm that in some cases it can be the case? Also I have tried to run this experiments without Adaptive camera model fitting and this strange behaviour preserves.

14

General / Camera calibration for UAV

« on: May 29, 2018, 12:24:26 PM »

I have a camera that used in UAV flights and I want to calibrate it.

In flight camera focus is set towards infinity, so when I try to calibrate camera I use this setting, but in this setting chessboard looks blured when I move camera in front of screen to cover full screen frame, calibration process seems works fine but do I do everything right?

Also can you clarify in Camera Calibration settings what is difference between Focal length (mm) and f parameter (according to documentation it's in pixel and also called focal length), is the same focal length just in different units or it's mean something different?

15

General / Measuring error by gcp points

« on: May 28, 2018, 07:07:41 PM »

I'm trying to measure error by gcp points, there are 3 of them, but for some reason error statistics is empty for 2 of them. Is it mean that error is zero? or is it indicates some problem?