Show Posts

This section allows you to view all posts made by this member. Note that you can only see posts made in areas you currently have access to.

Messages - SimonBrown

Pages: [1] 2 3 ... 5
Another update to the AccuPixel Metashape course - Manual Camera Calibration.

More details here:

General / Photogrammetry Academic Paper - SS Thistlegorm
« on: March 18, 2024, 11:30:24 AM »
It is with much pleasure I can finally share a co-authored paper I have been working on that covers the approach and methods used to record the wreck of the SS Thistlegorm:

A second paper will be following that covers the changes identified between 2017 and 2022.

We have updated our Metashape Professional course to include new topics:

  • Powerline detection
  • Working with multiple cameras

More on multiple cameras here:

As per our courses, the new topics include real world datasets to learn and practice with.

Its possible but depends on a few things...and is likely to need a script. Please drop us a line at the following page:

General / Re: Sparse cloud not updated after incremental alignment
« on: November 21, 2022, 11:52:37 AM »
6000 images is not so large dataset to align - what settings are you using and what format/size of images are being used?

I'm a little confused about the materials covered. The subject of this thread is "Accupixel Metashape Professional Online Training - Endorsed by Agisoft", but the link to the Accupixel site says "We are delighted to announce the availability of our new online training course for Agisoft Metashape Standard.
So does the course cover the Professional version?

Hello - the course content has evolved since we originally shared the post. I hope the following links help: - Foundation Course (Pro and Standard users) - Professional Course (Pro users)

General / Re: Lens not detecting chess board
« on: July 28, 2022, 10:25:08 AM »

Is there a way to manually calibrate the lens - trying to place points at the cross points of the checkers board?
If not, can i use calibration information from a different zoom? (I suspect not...)

Finally, I guess one other question. I have read that the automatic "calibration" when optomizing the camera positions is very good - so is it OK to not manually calibrate the lens?

The attempts I'm aware of - to manually calibrate a lens underwater using a chessboard - have proved unsuccessful.

Some observations:

Using a differing zoom to calibrate...will not ensure the path of light through the glass is consistent with the as-shot images used for reconstruction. Not recommended.

Metashape is very good with automatic calibration. There are some instances when manual calibration really pays off - we have provided consulting services to one massive civil engineering project client in North America on this - but the use case here sounds different.

ROV cameras can be a mixed bag...some good...some good at providing a visual feedback to the operator...but not all are going to deliver a result for photogrammetry.

So...some questions:

What camera is the lens attached to?
Are you shooting stills?
Or extracting frames from video?

General / Re: Processing large numbers of images - advice needed!
« on: February 14, 2022, 02:15:16 PM »
We have done some consulting work with the US National Parks Service such as this:

Happy to discuss further, if interested? Please use the Contact Us page:

General / Re: Using external drives (USB)
« on: February 02, 2022, 12:18:56 PM »
3.- Is it better to load pictures from one drive and write the project files on a different one or to do load the pictures and process the project on the same drive? (either built-in or external USB drives)
4.- Does the use of SSD drives improve the processing speed on any way?

Occasionally I forget to copy source images from a network share to the local SSD.

Things slow down you could say...but compared with other steps in the overall workflow its not hugely significant.

Its been so long since I used a mechanical as opposed to SSD for processing I cannot remember, but read/write speed isn't the greater bottleneck.

Processor speed and availability (or not) of GPU would be applying the limits.

General / Python Scripting Capacity and Capability
« on: January 17, 2022, 11:47:42 AM »
Both Jose and myself are delighted to announce that AccuPixel now has python scripting capacity and capability.

Its taken a while but we have taken the step to develop some in-house talent..

If you have a scripting requirement - automation/data manipulation/ocr text extraction as just a few examples - then please use the Contact Us page:

We look forward to hearing from you.

General / Re: Force Metashape to use manual tie points in Aligning
« on: December 19, 2021, 12:27:26 PM »
A minimum of 5 tie points are required for manual alignment.

Remember two things; firstly sequential really works best when used in conjunction with other parameters - specifically high accuracy GPS position data - and secondly sequential will not align images across parallel tracks. The step you see in the surface is therefore expected.

Suggestion; Run sequential. Then re run alignment with sequential off (generic) and reset alignment ticked off. This should at least align parallel track images.

As for bad qualify photos...they should be removed from the project and play no part in reconstruction.

General / Re: Photogrammetry with thermal images / water
« on: December 03, 2021, 12:11:24 PM »
The banks of the river - all things being equal - will be point-rich and align.

Are you using a drone? If the width of the river is not too great then a flight at altitude where both banks are visible might align to make a single model.

There is a risk with this as tie points may become clustered...not good.

The river itself? This will be interpolated, where the mesh grows its boundaries until either it a) meets another piece of mesh, or b) the bounding box or c) the algorithm calls a halt.

So the data in the river would be made might be possible to extract data from the aligned images. We are doing this with some data embedded in the jpeg (actually in the pixels...) and pulling it into machine readable format...

But without seeing the source data and understanding what the outputs are the above may be relevant...or not. Can you share anything?

General / Re: How to straighten a 'banana' scan in MS Std?
« on: December 01, 2021, 01:11:46 PM »
Curvature on long & thin objects is a common theme. Most are unaware their creation is...bent.

Fixing it might be possible...its not something I have encountered in my own work but here goes:

Constraints - requires Pro
Calibration - take a robust section of another chunk that does not show curvature and export the camera calibration. Then load it into this project. It *might* work. It might not. With calibration having constraints always helps. The problem with the std version is we won't really know how curved, or not, the section is - there is no way of validating what has been created.

Curvature is best avoided by doing long, thin runs.

General / Metashape Collision Investigation Webinar
« on: November 24, 2021, 08:19:02 PM »
Next month I will be delivering a webinar on using cost effective kit for #photogrammetry in conjunction the Insitiute of Traffic Accident Investigators.
An overview of Agisoft's Viewer and its benefits will be included too.

Its an event open to all and free. More details, including a link for registration, here:

Pages: [1] 2 3 ... 5