I’m trying to process the color information from point-cloud generated by pix4D. I think these color includes the deterioration information of iron structure. I found points having same coordinate with different color. these pair of points with same position were seen in adjacent rows of data in most case. What causes this? Which color should I select at this point?
[example]
x y z r g b
-58501.316 52594.446 472.838 191 199 146
-58501.316 52594.446 472.838 185 192 141
Hi,
the color of a pointlcoud point is obtained by blending the colors of the images used to reconstruct the 3D point. Since different images may be used to reconstruct different points, even if at the same 3D location, you can have some variability in the points colors.
The difference in the images color can be due multiple causes, such as changes in the scene illumination or to the in-camera processing, like automatic white balancing or exposure adjustments to mention a few of them.
As for how to deal with the color variance it is difficult for me to say, as it depends on the application you are targeting.
I think you could consider averaging the color of points at the same location, as that would be consistent with how we generate the color internally.
I understood its typical property of point clouds produced by SfM in sense of dealing with multiple images. As you suggested, I think averaging the color of points at the same position is a solution. The averaging may need some filtering based on difference of colors between the points of same location.
Thank you.