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Messages - MurrayW

Pages: [1] 2
1
General / Rapid Orthomosaic
« on: May 24, 2022, 12:55:42 PM »
Hi everyone,

I am looking for a method to generate a quick orthomosaic, so color can be checked and adjusted prior to the final mosaic.

I have 5400 images from FujiFilm GS100 100 MegaPixels)

I have psx project with 1100 of the 5400 images. It is aligned, optimised, Dense Pt Cld, Mesh, all ready to go to mosaic - that takes 7 hours.
But the colors differences between images are large due different dates, sun-angle, atmospheric conditions, etc.

I made some low resolution images, and made a new psx with those.
I did the  usual process and could generate a low-res mosaic in 2 minutes

I would like to import the EO (XYX/OPK.csv) from the accurate high-resolution psx - in place of the whole allign/optimise etc process with the low-res images

I hope to import and accept the EO
Also import a mesh or DEM, create a camera calibration, then run mosaic

But not sure how to tell metashape to accept the imported EO.


MetaSHape 1.7.5 build 13229 (64 bit)

regards

Murray


2
General / Steresocopic 3D mapping hardware
« on: February 28, 2022, 07:36:09 AM »
Hello everyone

I am using Metashape for processing vertical aerial photographs over 10 000 to 100 000 hectares.
We then export the cameras to Summit format and create Stereo 3D projects for mapping forests and vegetation, amongst other features.

I'm interested in hardware and software for stereoscopic 3D mapping, linked to GIS. 
I have been using Summit Capture for ArcGIS along with NVIDIA StereoVision 2 active LCD glasses with compatible monitor/graphics card.
But.... it's getting old and I may have to replace the whole set up soon.

Does anyone have suggestions for a new stereo 3D mapping setup?

Regards
Murray

3
General / Assign Imported DEM height values to dense point cloud
« on: October 23, 2020, 05:52:44 AM »
Hello,

(Agisoft Metashape Professional 1.6.1 build 10009 64 bit)

I am processing aerial photography and have generated a dense point cloud.
I have imported a Lidar DEM.

Can I assign height values from the Lidar DEM, to the dense point cloud?
Then subtract DEM values from dense point cloud z-values to determine height above DEM/ground?
I would then like to use the height above ground to classify ground and near-ground points.

Cheers
Murray

4
Thanks Paulo, 

opk2mat in place of ypr2mat = Omega Phi Kappa instead of Yaw Pitch Roll.

of course! 

I am a python-beginner...

cheers
Murray

5
Hi all/anyone.....
(Metashape Professional 1.6.1 10009 64 bit)

I am having problems with this script. 
As a test I set up a small block, went through the steps to produce an orthophoto  - and it is accurate.
I then exported cameras as type Omega Phi Kappa .txt and the camera calibration.

then I set up the exact same photos in a new psx
I imported the camera callibration, and  then the cameras as XYZ OPK
I used this script Tools/Run Script

Now the model has the photos incorrect - see attached image
In the Model Window, the photos are represented with what seems to be:
 -  Phi = almost 90; it looks like the aeroplane nose is pointing to the sky
 - Omega = almost 90; it looks the wings of the plane are pointing backwards/forwards

Thanks and cheers
Murray

6
General / Point Cloud height above ground
« on: March 18, 2019, 11:24:08 AM »
Hello,

How can I assign height above ground to the MetaShape point cloud?  I have generated a dense point cloud. I have an accurate Lidar DTM. Can I assign DTM value to points? 

In Forestry, LAStools does a process called "normalize" where the ground elevation is subtracted from the Point Cloud elevation so the point cloud represents height above ground - which is the height of trees.  This is an essential step for forestry information from point clouds - can MetaShape produce normalised Point Cloud?

thanks
Murray

7
General / Dense Cloud Display colors
« on: February 27, 2019, 02:52:53 AM »
Hi,

I have a dense point cloud derived from four band imagery. The point cloud is displayed as grey scale. The points have been colorized using Tools/Dense Cloud/Colorize dense cloud. I want to see the color of the points - Can the display of the point cloud be altered to show RGB color?

Regards
Murray

8
General / Re: Process four band images
« on: December 14, 2018, 03:18:45 AM »
Thanks Alexey.  That script works well.

Also, I have been learning about ImageMagick.

Here is some advice from experienced people:

"ImageMagick cannot write 4 channels to an RGB image using -combine. The fourth channel would be the alpha channel and it is added by -compose copy_opacity -composite. You can combine 4 channels as CMYK, if you want, but not RGB.

ImageMagick (6) does not write to multi-channel TIFF files right now as far as I know. It will write to multipage TIFF files by simply,

convert image1.tif image2.tif image3.tif image4.tif result.tif

See also https://imagemagick.org/script/command- ... php#define for -define tiff:alpha=associated|unassociated|unspecified for alpha specification"


9
General / Re: Mask Mesh build
« on: December 14, 2018, 03:14:03 AM »
Can resizing the bounding box be automated?

10
General / Mask Mesh build
« on: December 13, 2018, 05:37:58 AM »
Hello,

I am using Photoscan for an aerial photo project. The triangulation results are good, I've created a dense point cloud.

I want to build a mesh and PS reports that it will take 3 days.  But, I only really need a small area.  How do I limit the mesh build to be only a selected area?

I have manually selected points from the dense point cloud using the Model/free-form selection tool, reversed the selection, and deleted those points.  That works, I do get a mesh limited to the area of interest. 

However, I cannot automate that process. 

Can Photoscan:

     - import a shapefile to select points from dense point cloud?
or
     - use a shapefile to constrain the area for mesh build?

or does someone have a better method?

cheers
Murray

11
General / Re: Process four band images
« on: December 07, 2018, 01:17:17 AM »
Hi Alexey,

I replied before checking the output images....

The output is 32 bit floating point, whereas the input was 16 bit unsigned integer. 16 bit is required.  So no success yet.

There is also an error message ! name 'doc' is not defined

12
General / Re: Process four band images
« on: December 06, 2018, 01:07:17 PM »
Hi again Alexey

I ran your script and it worked very well.  Processng speed was quick - much faster than ImageMagick.

Thanks.

13
General / Re: Process four band images
« on: December 06, 2018, 03:54:46 AM »
Hi Alexey,

If I start project with 3 band tiff for align cameras, GCP and optimize cameras, can Photoscan then substitute four band 4 band (png or tiff) in place of 3 band tiff?

I want to use RGB for locating GCP.  The GCP are painted "X"on ground in white paint and dGPS +/- 2.5 cm. GCP is very visible on RGB, but is difficult to see on single band gray scale.

Once optimisaton/triangulation has achieved desired accuracy, I can use "Change Paths" to subsitute four band imagery. Will dense point cloud, and orthomosaic, have four bands?

cheers
Murray


14
General / Re: Process four band images
« on: December 06, 2018, 01:14:31 AM »
Thanks Alexey

I searched for ImageMagick commands to write a tiff without the alpha band, but I did not find a solution.

I did use ImageMagick to write to .png format and in that case the alpha channel is in a separate file and can be deleted.   When reading the ImageMagick commentary on file formats, they do not recommend tiff, because of so many tags and different interpretations.

I will use png to test processing.

cheers
Murray

15
General / Re: Process four band images
« on: December 04, 2018, 12:26:43 AM »
Hi Alexey,

Can you tell me how to remove alpha mark ? Actually, I am not certain that there is an alpha mark.

ArcMAP does not show an alpha channel. Band 4 can be displayed - see attached screen grabs.  Also, I exported to 4 band tiff from ArcMAP and Photoscan can now see four bands.

Band 4 comes from a different camera, with simultaneous exposure.  But, overlap is not 100%, so band 4 has zeros on two sides. Perhaps this is why Photoscan sees Alpha channel?

Maybe TIFF means: "Thousands of Incompatible File Formats" .....   :-/


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