Color Subsampling

[darkcloud]

Hello,
I am new to cloudcompare and am trying to analyze a bit of lidar data. The data is projected as 5 different colors (blue, yellow, white, grey, and black). When the file is uploaded, there is no scalar data. I am trying to separate the data into individual colors to be analyzed as 5 separate point clouds. Is there a way to do this directly in cloudcompare?

[daniel]

Well, it's not very easy, but you could try to play with the 'Edit > Colors > Convert to scalar field'. If you are lucky, using the last option ('Composite = R+G+B/3) will produce 5 different values (0 for the black, 255 for white, something in between for grey, 255*2/3 for yellow - hopefully not the same as the light gray ;) - and 255/3 for the blue). Then with the 'Edit > Scalar Fields > Filter by value' method you'll be able to produce sub-clouds corresponding to each value.

If two colors have the same 'composite' scalar value, you could still split them afterwards by selecting a single color dimension (R, G or B) and filtering again the corresponding sub-cloud.

[darkcloud]

http://imgur.com/rqQeRmq

This is the data I am working with. When I convert the point cloud to a scalar field, is there a way to check what scalar values match to which colors?

[daniel]

The easiest way would be to spawn a label on a point of each color (with SHIFT + left click on a point).