Messages

1

General / Re: Export per camera reprojection error as CSV

« on: February 26, 2018, 05:52:26 PM »

@Alexey

I know you are extremely busy answering numerous questions/requests each day.
Just hoping that this request is still on your radar.   

Thanks !

2

General / Re: Export per camera reprojection error as CSV

« on: February 07, 2018, 05:49:44 PM »

@Alexey
You are the likeliest person who might be able to help me obtain this.

3

General / Export per camera reprojection error as CSV

« on: February 06, 2018, 07:51:46 PM »

Hi,

I would like to know if there is a script that can perform a similar function as the export button in the reference tab to export per camera : image name, accuracy (m), error (m) and error (pixel) ? I am trying to export this data after camera optimization has been done.

Thanks,

Shwetank

4

General / Using calibrated parameters without recomputation

« on: June 12, 2017, 06:21:05 AM »

Hi,

If we have a number of calibrated images (both intrinsic and extrinsic parameters are available), how can we use agisoft photoscan to create a dense point cloud such that those parameters are used as is and agisoft does not to modify them ? For each image, the known parameters are: camera location (x, y, z), camera rotation (3x3 matrix), focal length in pixel, principal point, distortion parameters.

Thanks

5

General / Re: Transform for Projecting Point Cloud onto Orthomosaic

« on: March 30, 2017, 10:59:47 PM »

Hi JMR,

Practically, what you say is the exact operation I want to perform.   
However, the point cloud has (x,y,z) coordinates where z does not necessarily correspond to the axis of top-down flattening (makes sense ?).     
I am asking for the direction along which I do the flattening, unless the point cloud is always axis aligned and either one of the axes correspond to the cartesian coordinate space for the depth (or elevation) with respect to the camera flight.

Since it is an orthographic projection, only the direction of projection (the true vertically down direction) should be sufficient to get the desired result, which remains an unknown.

Thanks

6

General / Re: Transform for Projecting Point Cloud onto Orthomosaic

« on: March 30, 2017, 04:52:29 PM »

Hi Alexey,

Can you please help me in getting this working as desired ?
Could it be as simple as the vector from centroid of camera coordinates to the centre of the dense point cloud ? (but of course this is just a guess)

Thanks !

7

General / Re: Transform for Projecting Point Cloud onto Orthomosaic

« on: March 29, 2017, 08:05:47 PM »

Oh, got it.
That is definitely an easy solution to view it.

But if I was to do a mathematical projection operation, what would be the best way to obtain the plane along which I need to project the point cloud in order to get the desired alignment ?

I am trying to do the exported style of operations where I have the orthomosaic and the point cloud as separate files.

It would be great to know a transform (like a gravity vector), which can tell me the direction of projection. If I understand it right, an orthographic projection along that vector along any plane should line up with the orthomosaic.

8

General / Re: Transform for Projecting Point Cloud onto Orthomosaic

« on: March 29, 2017, 06:49:11 PM »

As usual, thanks for the prompt response Alexey !

It would be great if you can elaborate a little bit on the TopXY projection ...
Is it simple a vector (x,y,z) with x and y values set to zero and z = 1 or -1 ?
Also, how can I compute the distance factor to transform along the vector ? (assuming unit normal vector to orthomosaic)
Is it safe to assume that the orthomosaic is indeed along the z = 0 plane ?

Thanks,

Shwetank

9

General / Re: Transform for Projecting Point Cloud onto Orthomosaic

« on: March 29, 2017, 05:12:29 PM »

Any solutions to achieve this ?

10

General / Transform for Projecting Point Cloud onto Orthomosaic

« on: March 29, 2017, 03:38:29 AM »

Hi,

I recently started generating orthomosaic images using Agisoft and the quality of the results have been extremely good. I am trying to do a small experiment for demonstration purpose. I am tusing geotagged images for performing scaled 3D point cloud generation, and following up with orthomosaic generation.
Since the point cloud quality of the model at High density resembles the orthomosaic view very closely, the idea for the demo will be to show how I can project the points of the dense cloud onto the orthomosaic in a way that they line up correctly.
I am guessing there is a transform that can take me from the scaled point cloud (in metres) onto the 2D orthomosaic photo. The transform seems to be an orthographic projection but I am not able to compute the exact projection vector along which I should get consistently good projections. I have tried some random vectors based on hit and trial values, but obtaining the actual transform will be very helpful.
The goal is to show how well the projected point cloud lines up with the orthomosaic. Furthermore, I am trying to show dimensions in each and show that the dimensions in the 2D orthomosaic is the same as the scaled point cloud.

Thanks,

Shwetank

11

General / Re: Camera Centers not correct in certain projects

« on: March 16, 2017, 05:59:26 PM »

Hope this topic is not marked as solved yet   

12

General / Re: Camera Centers not correct in certain projects

« on: March 15, 2017, 11:26:30 PM »

Hi Alexey,

I tried what you suggested, and that worked for getting the cameras and the 3D point cloud in the same reference coordinate system. But, this led to loss of GPS scale data in the point cloud. (ResetTransformChurch.jpg - attachment)

Is there a way to do the above while keeping the GPS scale ?

What I am really trying to do it to scale the point cloud using the GPS data in the images, and get a scaled point cloud in meters (in local coordinate system). Then I want to overlay the cameras (with parameters expressed in same local coordinate system) for the GPS scaled point cloud.

It seems like I am missing some transform trick ... (which is in front of me somewhere but I can't find it)

Thanks !

13

General / Re: Camera Centers not correct in certain projects

« on: March 15, 2017, 07:17:07 PM »

Thanks for that information Alexey !

Just to verify that I am doing the steps correctly,

If I have performed a 3D point cloud generation using geotagged images with exif data, I need to do the following if I export the point cloud in local coordinate system :

=>  Go to chunk properties, and select reset transform. Then export cameras and point cloud (in local coordinate system)

Following this, the camera centers should work based on my initial approach.

I really appreciate the prompt help.

14

General / Re: Camera Centers not correct in certain projects

« on: March 15, 2017, 05:03:10 PM »

The point cloud was exported in the local coordinate system (but the images had embedded GPS data).
I will try to re-run the project and repeat the steps after stripping out all the camera and GPS data to remove that variable.

Is there a chance that some internal transform is throwing my calculations off ?

15

General / Re: Camera Centers not correct in certain projects

« on: March 14, 2017, 07:35:21 PM »

Hi James,

I tried what you suggested but it doesn't seem to give me the correct camera centers. Please look at the attached image (red are the original centers, green are the ones that I get after implementing your suggestion).
I would like to attach the point cloud file but the attachment limit prohibits that.

Thanks