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Author Topic: What needs doing to be able to use Reduce Overlap command ?  (Read 3176 times)

Steve003

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What needs doing to be able to use Reduce Overlap command ?
« on: October 15, 2021, 12:01:22 AM »
Hi,
Metashape 1.7.4
Tools>Reduce overlap command.
It is greyed out, what do I have to do to be able to pick it ?
I have just aligned 155 images and threw some extra ones in to try and plug some gaps, so some are needing removal as they share same location or thereabouts.
I have obviously got turned on show camera locations.

I tried selecting all but still that command is not available.  :'(

Steve

Alexey Pasumansky

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Re: What needs doing to be able to use Reduce Overlap command ?
« Reply #1 on: October 15, 2021, 12:19:42 AM »
Hello Steve,

Reduce overlap feature requires mesh model (at least rough model) as overlap estimation is based on the polygonal surface (and images being projected on it).
Best regards,
Alexey Pasumansky,
Agisoft LLC

Steve003

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Re: What needs doing to be able to use Reduce Overlap command ?
« Reply #2 on: October 15, 2021, 12:29:34 AM »
Hi Alexey, I thought by removing what are many overlaps it would be less taxing on the process, before continuing, as by the time a mesh is made its had to work with far more photos than needed and surplus to requirements.

It is tricky to select a set of photos and have an idea of their coverage, you think you have got it right then you find overlappers and gaps !
I aded more photos to fill gaps and ended up overlaps as well.

I can see the overlaps in show cameras, can I select a photo I dont want to use in the show cameras view and delete it and the associated image, perhaps first have it load it on screen to see which of the two is worse ?

This would make sense.

Is it not possible though as it knows where the camera positions are, to have it identify the overlappers in sparse point cloud ?

Steve

Alexey Pasumansky

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Re: What needs doing to be able to use Reduce Overlap command ?
« Reply #3 on: October 15, 2021, 12:39:22 AM »
Hello Steve,

If the actual scene is not too complex, you can generate a rough model from the sparse point cloud and run Reduce Overlap command.

Selected cameras in the Model view can be removed straight away or you can use Filter Photos by Cameras command in order to show only selected cameras in Photos pane for more convenient navigation between them.
Best regards,
Alexey Pasumansky,
Agisoft LLC

Steve003

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Re: What needs doing to be able to use Reduce Overlap command ?
« Reply #4 on: October 15, 2021, 03:01:40 AM »
Hi Alexey,
Many thanks for replying.
I count 93 'no entry' signs beside my photos in the image panel having run make mesh source sparse point cloud then remove overlaps setting of 3 (whatever that means)

I presume the red no entry signs are the images to be removed, however selecting a few of them they are those that are the only images  for the central face of the wheel and vital to the build. Maybe that icon means they are for keeping, so I select one without and again its a crucial image, so I am uneasy if not scared stiff of this, there is no undo that command.

as I had 155 I could see maybe 20 images at best, but not 60% needing removal. To me thats going to weaken this as I never would have gone for 62 images to form it.

Quote
Selected cameras in the Model view can be removed straight away
I can see an overlap image, I cant select it in the model view though.
I am with the navigation tool (V) is there a special tool or key to hold down to select a camera position/image in the 3D model view ?

I am still happier to select an image in model view and delete it but cant see how to do that.

I google filter photos by camera metashape and see nothing, I use the manual and it finds nothing.
Where is this command, there is no command line to type commands like in Rhino3D.

If this might be better how do I undo the 93 selected images, there is no edit undo for that overlaps command.

Steve

Alexey Pasumansky

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Re: What needs doing to be able to use Reduce Overlap command ?
« Reply #5 on: October 15, 2021, 04:23:42 PM »
Hello Steve,

The result of "Reduce overlap" feature is the set of disabled cameras. Disabled cameras are marked with the "no entry" sign - such cameras wouldn't be used in further processing operations, such as depth maps, mesh and texture generation. (see disabled_photos.jpg attached).

If you want to delete the disabled cameras, then switch the Photos pane to Details view, sort the cameras in the list by the Enabled column (by default it could be the very last column), select the disabled cameras, right-click on selection and choose Remove Cameras option in the context menu. (see remove_cameras.jpg attached).
In case you need to enable some of the disabled cameras, right-click on their thumbnails in the Photos or Workspace pane and choose Enable Cameras option. It also works for cameras selected in the Model view.

In case you need to select the cameras in the Model view and review or delete them, you need to switch to any convenient selection tool, select the cameras (so that the camera placeholders are highlighted with red), then right-click in the Model view and choose Filter Photos by Cameras command from the context menu. As a result, only selected cameras will be shown in the Photos pane.  (see filter_by_cameras.jpg attached).
Best regards,
Alexey Pasumansky,
Agisoft LLC

Steve003

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Re: What needs doing to be able to use Reduce Overlap command ?
« Reply #6 on: October 15, 2021, 06:21:53 PM »
Hi, the problem was overlap cameras found 93 images, these had the red icons, so as I first thought red was disabled, but far more than I could see needed removal,
the command made for a new scary situation, either a lot of unselecting them, or ?

so to undo the selection go into the photo panel and sort out the problem there.

If it had found those that did overlap, ok, but it found many that were perfectly ok. 93 versus 20 or so. leaving massive gaps in my coverage.

I can see myself only using manual selection , though I cant manage to do that yet. Nothing selects.

Quote
In case you need to select the cameras in the Model view and review or delete them, you need to switch to any convenient selection tool, select the cameras (so that the camera placeholders are highlighted with red), then right-click in the Model view and choose Filter Photos by Cameras command from the context menu. As a result, only selected cameras will be shown in the Photos pane.  (see filter_by_cameras.jpg attached).

I have just done mesh from sparse point cloud, and I am unable to click on a camera, what am I doing wrong ? You said they can be selected in a model window with mesh made, but I cant get them to . I am using the arrow tool immediate left icon to the selection dashed line tools, the one that can tumble a perspective view or moves ortho views etc. The arrow tool as we know it. click the little thumbnail with its black line and nothing.
I try the crawling ants selection tool which requires dragging around an item , and after a few attempts it goes pink, I experiment and finf that you need to totally capture the black line not the image , then the image goes pink edged. so arrow tool not of use.
I then wish to see the photo large, wish a double click showed the photo, need to find it in the photos panel, then launch it. A right click disable photo deals with it.

In order to get at its black line I had to zoom in a great deal else I was getting both of them. But in fact one needs both of them to decide which is best, so with hindsight no need to get one, select both !

I will send the photo set to you as a support case. take a look. It should have dealt with those I could see overlapping.

Steve
« Last Edit: October 15, 2021, 06:47:36 PM by Steve003 »

Alexey Pasumansky

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Re: What needs doing to be able to use Reduce Overlap command ?
« Reply #7 on: October 15, 2021, 06:43:26 PM »
Hello Steve,

Quote
I have just done mesh from sparse point cloud, and I am unable to click on a camera, what am I doing wrong ? You said they can be selected in a model window with mesh made, but I cant get them to . I am using the arrow tool immediate left icon to the selection dashed line tools, the one that can tumble a perspective view or moves ortho views etc. The arrow tool as we know it.
You need to switch from Navigation tool (arrow) to Selection instruments and draw the selection, that includes the cameras (the ends of the black lines - opposite to the blue rectangles, representing the cameras).
Best regards,
Alexey Pasumansky,
Agisoft LLC

Steve003

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Re: What needs doing to be able to use Reduce Overlap command ?
« Reply #8 on: October 15, 2021, 06:50:27 PM »
Hi, you were typing whilst I was struggling, and I found out what you have said, ha !
its the black line thats the thing that matters, getting the little image doesnt do it.
A lot of zooming in to just select them and nothing else is required.
Wish there was an instant way of launching the image large, or both of them to compare. Need to find them in photo large thumbs and launch them.

Steve

CheeseAndJamSandwich

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Re: What needs doing to be able to use Reduce Overlap command ?
« Reply #9 on: October 17, 2021, 03:55:47 PM »
I think the Reduce Overlap's Surface Coverage value is the number of photos where a point/feature is seen in...  Correct Alexey?
I use 9...  so a point on a rock, that MS has recognised and put a tie point on, is seen in up to 9 different photos, from 9 different angles...
The nature of my scanning, swimming around with GoPros taking 2s timelapse photos, means that i always land up with too much overlap for each photo, often overlapping tracks, so too many images.  Using the Reduce Overlap's Surface Coverage value set to 9 usually disables about 1/3 of my cameras.  And removing these absolutely speeds up the depth maps and meshing heaps!!!

My procedure:
Align all photos.
Try to align the unaligned (reset & align selected)
Gradual selection Recon & Proj set to only 15, it removes a lot of the weak points.
optimise cameras.
Create mesh from sparse cloud (VERY QUICK!)
Reduce Alignment set to 9
Photo Pane, sort by Enabled, select all the unticked, remove selected photos.  This deletes 1/3 of the cameras.
Optimise cameras again
Create mesh from Depth maps...

Just save your model before you run the Reduce overlap command, and then just reload it trying different values, until you find one that's removing just the right amount.
« Last Edit: October 17, 2021, 04:03:07 PM by CheeseAndJamSandwich »

CheeseAndJamSandwich

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Re: What needs doing to be able to use Reduce Overlap command ?
« Reply #10 on: October 17, 2021, 04:02:05 PM »
If the actual scene is not too complex, you can generate a rough model from the sparse point cloud and run Reduce Overlap command.
Alexey,

How do you define 'not too complex'???

I create the sparse point cloud derived mesh with the default setting, and it creates it very, very quickly!!!  Even with the sparse point cloud generated from 20,000 cameras...
Should i, could i up the settings so the sparse point cloud mesh is even higher quality?  Otherwise i have to wait 24 hours for it to create a mesh from the all 20,000 cameras...
What kind of complex scene shouldn't use the sparse point cloud?