Messages

61

General / Re: Radiography - 3D imaging

« on: July 21, 2022, 11:15:27 AM »

I have found this.

http://blogg.vm.ntnu.no/xraynet/2015/04/28/using-photogrammetry-on-digital-x-ray-images-2/

Looks like it was done with the former Photoscan in 2015.

62

General / Re: Close-Range Photogrammetry with Local Coordinates doubts

« on: July 20, 2022, 02:30:07 PM »

Hi Frmoraes,

yes and don't forget to shoot oblique photos too, the better the photo intersection the better the bundle optimisation.
If I were you, I would investigate in what is the best camera configuration and have a look at camera calibration too.

Best regards and success,


Kiesel

63

General / Re: Radiography - 3D imaging

« on: July 20, 2022, 02:20:27 PM »

Alexey,

Ah yes that was a funny one by Mark Florquin! 

64

General / Re: Markers show on wrong location (photos and sparse cloud) and with huge errors

« on: July 19, 2022, 04:00:14 PM »

Hi Lukas,

perhaps there is a mix of photos with and without GNSS EXIF-data? Have you already disabled all photos in reference pane? (To be absolutely sure you can erase GNSS EXIF-data and try again, but leaf camera data intact, because you have a lot of different cameras when using tourist photos.) There is also the possibilty that single cameras can't be well calibrated, if you use a lot of tourist photos only and not against a well calibrated general camera.

My work-around if we don't find a solution would be to copy my professors project and slowly add my new images to it and align them. If it fails at one point I know which pictures are bad for the alignment. It will take some time but it's the only thing I can think of...

  You can do that already in the workspace pane by de/activating single cameras.

Best regards,

Kiesel

65

General / Re: Close-Range Photogrammetry with Local Coordinates doubts

« on: July 19, 2022, 11:37:27 AM »

Hi Frmoraes,

About the cardboard, I'll change this scenario. In my new test, I'm going to put the markers on the body of the object (that is wood).

That's better!

The coordinate system I've got with a total station was set to X=1000; Y=5000; Z=100. And as you said Z is the height. For the Metashape, I firstly changed Z_axis with Y_axis, and then I got photo4 as result.

I wouldn't do this, because it isn't necessary. Also your wooden plate isn't standing vertical as can be seen in photo 2. You can later easily define an (orthogonal) orthomosaic and DEM to markers at the wooden plate.

In one of my future tests, I'm going to add oblique pictures (something like a Maltese Cross configuration) and compare the results with only "central" pictures.

Good!

When you said about adding +/-90° and 180° rotated pictures, I should take just some pictures in this configuration, or I should take again all the pictures in this configuration?

Only some are enough.

Also you should tick the local coordinate system for markers reference in reference settings.



Kiesel

66

General / Re: Radiography - 3D imaging

« on: July 19, 2022, 09:43:35 AM »

Hi JakubZaruba,

I don't think that you'll have success with Metashape or any other photogrammetry package, because normal photogrammetry works with the laws of reflection and central perspective only and not with translucent materials.

Probably you'll have more success with mathematics and software used in computer tomography.


Best regards,

Kiesel

67

General / Re: Close-Range Photogrammetry with Local Coordinates doubts

« on: July 19, 2022, 08:56:11 AM »

Hi Frmoraes,

I'm surprised that you use such unstable material as cardboard for such task, you will not get good results with it.

The coordinate system you get with a total station differs to that in your pictures, where normally z is height and not y. Perhaps that's causes the problems you have after importing coordinates.  How is your project coordinate system defined? Could you show the Reference settings window?

Exclude stationary tie points is for turntable tasks, which you don't have.

For such task, analyze deformation of concrete beams, it is important how the pictures are taken. I can recommend to take pictures like you do for camera calibration, so add +/-90° and 180° rotated and oblique photos to get a stable camera configuration and good camera calibration.

Best regards,

Kiesel

68

General / Re: Problem with using depth maps of Google Pixel smartphones

« on: July 14, 2022, 11:51:01 PM »

The Agisoft team is working on it.
So there is some hope. 
Perhaps you send them some photos with depth maps made with your phone too to help to solve the problem.

Kiesel

69

General / Problem with using depth maps of smartphones

« on: July 11, 2022, 03:31:30 PM »

Dear Agisoft team,

Today I tried to follow your article https://agisoft.freshdesk.com/support/solutions/articles/31000162212-smart-cameras-with-depth-sensor-data-processing with photos made with the Google Pixel 4a 5G, but when I import those photos with 'File/Import/Import Laser Scans...' and then choose all photos with 'Dynamic Depth Image (*.jpg *.jpeg) after that Metashape opens surprisingly the same folder again, which now seems emty, to choose a folder. When I go one folder up to choose the same folder, with the photos in it, I get an error message (see appendix) that Metashape can't read the embedded depth data. As result none photos are imported.

To make sure that the photos have embedded depth data I have imported one in Photopea, with the result, that they have 4 layers (see also appendix)
Layer 1 white filled depth data layer
Layer 2 depth map
Layer 3 original photo
Layer 4 with depth data processed photo

In advance to any help

best regards,

Kiesel

70

General / Re: Dense points genereation from images that mounted on a car

« on: May 16, 2022, 09:46:34 AM »

Hi JyunPingJhan,

I think the camera you have choosen isn't the right one to get a good pavement inspection. You use only a very small part of your sensor for that (less than 50%?, most of the photo area is masked out) and additional the camera looks at a very low angle at the pavement, which isn't good for inspection too.
I would rather use a normal camera facing down to the street for that what you want to get. The camera needs to be mounted on a higher point for that. This way you don't have the problem with the unwanted pairs too.


Best regards,

Kiesel

71

General / Re: confused: from sparse cloud to dense cloud

« on: May 06, 2022, 10:18:38 PM »

Hi René,

Sorry for the confusion. My sentence:

Btw. it is the same for the step from the dense cloud to the model, where an edited dense cloud has no impact to the model (you will see the out edited parts in the model again).

wasn't precise enough.

It depends on the method you choose for model calculation. When you choose
a) from depth maps, my sentence is right
b) from dense cloud, the out-edited parts in the dense cloud aren't used for model calculation.

Hope it makes more sense now.


Regards.

Karsten

72

General / Re: confused: from sparse cloud to dense cloud

« on: May 05, 2022, 08:58:34 AM »

Hi renevg,

the sparse cloud is the result during the aligning step. You can then use 'Model/Gradual Selection' to edit it for:

• Reprojection error
• Reconstruction uncertainty
• Image count
• Projection accuracy

Don't forget to reoptimize your cameras after that to get the improved camera extrinsics (positions and orientation) and intrinsics (internal camera parameters).
With this new parameters (extrinsics+intrinsics) the dense point cloud will be generated, the sparse cloud isn't used for that at all. Btw. it is the same for the step from the dense cloud to the model, where an edited dense cloud has no impact to the model (you will see the out edited parts in the model again).

So if you want to exclude something in your dense cloud or model you need to mask those parts in the input photos.

Best regards,

Karsten

73

General / Re: High Definition 3D model of a 30cm. statue in a museum...

« on: April 05, 2022, 09:52:01 AM »

Cyber Simon,

Don't forget to put in the scene a color reference target and some scale bars like these:
http://palaeo3d.de/WP/?page_id=23

You might also find some helpful tutorials on Dr. Heinrich Mallison's page, even most of them are a little older now:
https://dinosaurpalaeo.wordpress.com/author/heinrichmallison/



Best regards,

Kiesel

74

General / Re: Multi-camera rig vs. Station

« on: March 23, 2022, 12:26:19 PM »

Hi sepher,

you can look for details in the 'Rigid camera rig data' section in the manual at page 23 (page 29 in PDF) and the following pages:

The first subfolder camera will be automatically set as master camera in Camera Calibration dialog, the rest of the cameras will be tackled
as slave cameras to the master. ....

Kiesel

75

General / Re: Multi-camera rig vs. Station

« on: March 22, 2022, 10:53:09 AM »

Hello sepehr500,

1. A camera station assumes that all photos are shot around the projection center (NPP no parallax point). Your multi cammera rig doesn't fullfill this.
2. The projection centers of all 4 cameras have different positions (offsets to each other), that's why they need to be handled as multi camera rig in Metashape.

For that organize the photos from every single camera in an own folder and put all 4 folder in another one (the number of photos in every folder need to be the same). You then can call that upper folder in Workflow/Add Folder and choose Multi-camera system. In the camera calibration dialog you can input offset values for a precalibrated rig. Your multi camera rig will be calibrated in camera alignment process.

Best regards,

Kiesel