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Messages - rossnixon

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General / Re: Fast orthomosaic without build Dense cloud?
« on: September 14, 2019, 12:17:39 PM »
Is this from overlapping aerial photos? If the ground is relatively flat, use 'Image Composite Editor' a free image stitching program for Windows.  You will then have to georeference the final image in a mapping program.

General / Re: View errors - orders of magnitude changed?
« on: September 09, 2019, 07:15:04 AM »
I have never entered or changed the precision/accuracy of my GCPs. Perhaps I should.
That doesn't explain why my errors have changed to about 100x smaller. Only the Metashape version has changed.

I have changed the precision to 5m for the points I kept. That looks more like it used to be.
Is there somewhere that I can set a default precision? (It is likely to be similar for all projects).

General / Re: View errors - orders of magnitude changed?
« on: September 09, 2019, 02:48:43 AM »
Here is a small old (July 2017) model which would have had errors of more than 1 or 2m per point.

Ross Nixon

General / View errors - orders of magnitude changed?
« on: September 06, 2019, 08:10:21 AM »
Within the last few months, a new version of MetaShape has been showing me errors in my project which are perhaps(?) 100x smaller than usual.

 I have opened some old PSZ files to check and these also have the unusually small errors. I am typically getting errors of 0.004m, whereas I would normally expect around 1-4m.

This is for aerial models. Sorry but I didn't record the date or version when this occurred.
Has anyone else seen a large reduction in their errors?

General / Re: GCP Pinning - Photogrammetry mapping
« on: September 04, 2019, 07:27:26 AM »
I can't say I've noticed that problem. I pin a marker to a GCP  in two adjacent photos. Then I do that for two more markers. Then I do Update & Optimize Alignment. I guess it depends how close "reasonably close" is to you. Come to think of it, you might be correct - I recall some showing up further away than I expected.

General / Re: The most effective way to make a scan from many photos?
« on: June 30, 2019, 03:33:43 AM »
Your question is strange. What do you mean by make a scan? Do you mean produce an orthophoto?

General / Re: jpg + jgw
« on: May 04, 2019, 10:22:59 AM »
The fact that there is a .jgw (world file) means it is georeferenced and rotated to north in a particular projection.
Open the .jgw file with NotePad.
You will see the (ground) size of each pixel in metres.
You will see the X-Y coordinates from the middle of  the top-left pixel. The will be from one of the UTM projections.

General / Re: jpg + jgw
« on: May 04, 2019, 03:28:29 AM »
The photos you linked to are georeferenced orthophotos. They are *outputs* from a program such as Photoscan. They can't be used to create DEMs.

General / Alignment problem - 1.5.2 build 7838
« on: April 04, 2019, 03:39:43 AM »
I have four parallel overlapping runs of (vertical) aerial photography.

Using Generic Preselection, I can only align the first two runs, no matter what other settings I use.

If I disable Generic Preselection, I can only align the OTHER two runs.

I have saved these as two separate PSX files.

Is there some way to merge the two jobs? Or should I just process them separately?
The only requirement is an orthophoto. Do not need an accurate DEM.

Have other people had alignment problems with version 1.5.2?
Should I install version 1.4 as a parallel installation and try with that?

General / Re: System requirements - where is my fault ?!?
« on: March 04, 2019, 03:32:53 AM »
If on Windows, note the exact time of the crash (to the nearest 5 seconds even).
Then look at your Event Logs, especially the System ones. They will often be a very strong clue as to what went wrong.

Bug Reports / Re: 4GB Max file size when exporting orthophoto
« on: March 03, 2019, 04:26:22 AM »
Will it delete after you restart the compter?
If not, try one of these:

General / Quick and dirty mosaicking - possible?
« on: December 24, 2018, 05:45:48 AM »
Is it possible to create a 'quick & dirty' mosaic from hundreds of well-overlapped aerial images (GPS data is in images)?
The land is mostly quite flat.
Don't need georeferenced output.
Don't need any height info.


General / Re: computer performance question
« on: October 02, 2018, 03:48:18 AM »
It certainly could Alvin. I've processed 2000 photos (5472 x 3648px) using a 2nd gen i5-2500k (overclocked) with *onboard* graphics only. Sure, it takes a *long* time though.

General / Re: Balancing dense cloud specs vs mesh specs
« on: August 29, 2018, 02:04:33 AM »
Hi Alexey,
Any comments on the values I used?
Also, what effect would disabling interpolation have on the orthophoto?

General / Re: Balancing dense cloud specs vs mesh specs
« on: August 20, 2018, 02:10:44 AM »
Hi Alexey,
Details are all in my PDF report here
Some of the values you will see are
254 images: 5472 x 3648 px
Key/Tie point limits: 80,000 / 20,000
Tie points: 471,998 of 699,990
Dense cloud points: 122,457,855

Windows 10 with 16GB of RAM.

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