manage with photoscan 4 simultaneous cameras

[mfran2002]

Hello,
I have a drone with 4 cameras (multispectral cameras: RGB, RED, GREEN, BLUE-NIR).
The work area is precision agriculture.
To give complete info, cameras are MAPIR survey1.
I shot photo sequence and finally I got 4 simultaneous photos from them for each shot.

Now I have some doubts:

1. how can I manage those photos into photoscan?

I thought to create a chunk and add all of them into (I will have 4 copies of the same area, one for each camera).
Then I thought to proceed with the usual workflow (basically: quality estimation, alignment, dense cloud, mesh, texture)
Is it correct?
Or have I to create a separate chunk for each camera and then merge them?

2. when I create the 4 XML files from LENS (one XML with calibration parameters for each camera) how can I import those into photoscan?

Many thanks in advance for your help!
m

[Alexey Pasumansky]

Hello mfran2002,

I can suggest to create four separate folders and split the data accordingly - each folder should contain only images from the certain cameras. Then use Add Folder option and specify the updir containing all four folders in the file browser window and click OK.

In the opened dialog you need to select create multispectral chunk option.

To use different calibration data for each camera you should load the external calibration file to each Plane in the Tools Menu -> Camera Calibration window.

[mfran2002]

Very thanks for your explanations Alexey.

I've just tried and, in the dialog box, I have 4 choices:

1. create camera from each file
2. create chunk from each folder
3. create multiframe cameras from folder as cameras
4. create multiframe cameras from folder as frames

may you suggest me the right choice?

thanks!

[Alexey Pasumansky]

Hello mfran2002,

It should be "Create multispectral cameras from folders as bands".

Which version of PhotoScan you are using?

[mfran2002]

currently 1.0.4

[Alexey Pasumansky]

Hello mfran2002,

You should try version 1.2.4, as the approach has been implemented in the version 1.2.

[mfran2002]

Ok, I will try to update (I'm not so skilled, hope to be able)

after having chosen the correct option I will have 4 chunks?
for each of them I will load its own calibration xml file from lens, right?

[Alexey Pasumansky]

After updating (you just need to download the latest installer and run it over the existing version) and choosing the correct option you'll have one chunk with the number of camera instances equal to the number of camera positions (not the total number of images for all the four cameras). Then you need to go to the Tools Menu -> Camera Calibration window where you'll see Planes combobox on top of the dialog (usually not displayed for common surveys), so you need to switch between Planes and load the calibration file for every plane. The order of the planes is similar to the order of the folders.

[mfran2002]

Hi Alexey,
upgrade done but I have a doubt; what do you mean when you say:

you'll have one chunk with the number of camera instances equal to the number of camera positions (not the total number of images for all the four cameras)

I've tried with a little example: 4 folders, 2 photos per folder (so, a total of 8 photos)
and after having chosen the option "Create multispectral cameras from folders as bands", the system give me 1 chunk having only 3 cameras (3 photos I guess...)

I don't understand, please may you help me?
thanks!

[Alexey Pasumansky]

Hello mfran2002,

Can you send those photos packed to archive to support@agisoft.com? We'll check what could be the issue.

According to the folder and file layout two cameras should be added each having 4 planes (meaning four sensor camera rig and two camera positions).

[mfran2002]

sure Alexey, I will send you the photos
consider that they are simply a test (4 photos per band)

an update: this morning I've tried your suggested procedure, but the system returns to me (I guess) only the perform of one camera (BLU-NIR), that correspond to the first folder in the updir...

In the email with the photos, I also will send you the log of the steps (add folder with choice of multispectral per bands, loading of xml calibration file per plane, alignment, dense cloud, mesh, texture)

thanks, bye
m

[mfran2002]

package with 4 dirs and log from console sent

[Alexey Pasumansky]

Hello mfran2002,

Thank you for sending the sample data.

From what I see on the first glance: you have different number of images in the folders (four and five), but the number of photos should be the same (and the order of the images should be in correspondence as well). Also the images in each folder are three-channel RGB images, it means that for four-camera rig you've got 12 channel in such approach, that seems to be incorrect. So you probably should convert the images to the single channel TIFF files (all except RGB) prior to loading the data to PhotoScan and processing.

[mfran2002]

sorry Alexey,
I put the wrong folders in attachement (simply added one photo to blu-nir and to green, you can delete the last one photo for each of them)

I tried the first test with the same number of photos per folder (4 photos per folder) and with the same correspondence order of the images (then tried to change something...) with the same incorrect result.

Concerning the conversion of the images to the single channel TIFF files (all except RGB) prior to loading the data to PhotoScan and processing, may you please tell me how to do it? 

consider that in a "real" photoscan elaboration I will have 100/200 photos or more per band

thanks a lot for your help!

[Diego]

Indeed I have the same problems, I think there is something wrong with the program. The same incorrect result.