Search found 12 matches

by manatttta
Wed Sep 30, 2015 9:24 pm
Forum: Questions
Topic: Rendering and Picking
Replies: 1
Views: 2708

Rendering and Picking

Hello, first of all congratulations for the CloudCompare software. I think it really outperforms Meshlab in a series of ways, has a much more clean code, and has great ideas implemented. Altough, I notice it can be somewhat slow in rendering large point clouds. I have some simple questions that I've...
by manatttta
Mon Mar 30, 2015 9:45 pm
Forum: Questions
Topic: Collinearity equations: from image to world coordinates
Replies: 1
Views: 1883

Collinearity equations: from image to world coordinates

Hello,

how can one use the collinearity equations parameters (estimated with the Bundler import interface), to transform a given image point to the world coordinates?
by manatttta
Thu Oct 09, 2014 10:48 am
Forum: CCLib
Topic: Orthomosaic Computation
Replies: 17
Views: 60857

Re: Orthomosaic Computation

Hello, I managed to get some results. However, some images, on the extremes, are getting a lot of distortion (as we are projecting the images to the same origin).
Maybe we have to shift the cameras a bit as we build the mosaic. I can show you some results and I can give you my code, just tell me how.
by manatttta
Wed Oct 08, 2014 10:02 pm
Forum: CCLib
Topic: Orthomosaic Computation
Replies: 17
Views: 60857

Re: Orthomosaic Computation

I think that is correct. And that is simlar to what is implemented in OrthorectifyAsImage.
But you use the a0, a1, a2, b0, b1, b2, c1, c2 indices estimated with your optimization routine. However I want to project those points with R and t from Bundler. Is this what you are thinking?
by manatttta
Wed Oct 08, 2014 8:24 pm
Forum: CCLib
Topic: Orthomosaic Computation
Replies: 17
Views: 60857

Re: Orthomosaic Computation

Yes. I want to project all image pixels on the same plane, but using the R and t matrices from Bundler, with intrinsics.
But I was trying to do the math I could not deduce how Z = Z0 results in those equations.
by manatttta
Wed Oct 08, 2014 8:07 pm
Forum: CCLib
Topic: Orthomosaic Computation
Replies: 17
Views: 60857

Re: Orthomosaic Computation

From the Bundler manual, we have that We use a pinhole camera model; the parameters we estimate for each camera are a focal length (f), two radial distortion parameters (k1 and k2), a rotation (R), and translation (t), as described in the file specification above. The formula for projecting a 3D poi...
by manatttta
Wed Oct 08, 2014 7:40 pm
Forum: CCLib
Topic: Orthomosaic Computation
Replies: 17
Views: 60857

Re: Orthomosaic Computation

That I understand. I don't understand why this needs another parameter estimation and does not use the outputs from the Bundler. Do you understand how the x= (Z-Z0)... Y=(Z-Z0)... degenerates in those simple equations? I think the key to the problem relies on that. Another question, how do you proje...
by manatttta
Wed Oct 08, 2014 6:59 pm
Forum: CCLib
Topic: Orthomosaic Computation
Replies: 17
Views: 60857

Re: Orthomosaic Computation

What I dont understand for now is that you are not projecting the 3d points onto the orthorectified image: you are using the 2d points from the original image.
by manatttta
Wed Oct 08, 2014 4:11 pm
Forum: CCLib
Topic: Orthomosaic Computation
Replies: 17
Views: 60857

Re: Orthomosaic Computation

Hey, I am trying to use the R matrix from Bundler to compute the a[3], b[3] and c[3] vectors. It is not working. I have been struggling to understand the following equations in the orthoRectifyAsImage function Here you are computing the image extrema: xi = -halfWidth; yi = -halfHeight; qi = 1.0 + c1...
by manatttta
Wed Oct 08, 2014 1:29 pm
Forum: CCLib
Topic: Orthomosaic Computation
Replies: 17
Views: 60857

Re: Orthomosaic Computation

Ok, I am going to try and use it and if you are interested i can show you some results. Thank you very much