Remapping Intensity Values

[patch]

Hi,

Firstly, apologies if this has been asked before as I'm sure it's a fairly simple issue. I have looked through the forum and haven't found/understood the answer I need yet.

I currently have a pointcloud which I am visualising in Pointools.

I export it as an .xyz from Cloud compare in an XYZIRGB column structure.

The issue is that certain parts of the cloud have very dark intensity values and I am trying to find a way to remap the values so that the darker parts of the cloud are lighter.

So far I've been trying to do this using the Edit>Scalar Fields>Arithmetic function on CC, in which I can multiply/divide/square etc. the Scalar Field by a constant.

It is a bit of a trial and error approach right now and was wondering if anyone could help me find a mathematical logic which will decrease the 'contrast' of the Scalar Field overall (similar to how you might on Photoshop for example).

I am not looking to remove the darker points, simply remap them so that they are lighter.

Any help appreciated and can post screenshots if that is helpful.

Cheers.

[daniel]

Hum, sadly there's no 'contrast' enhancement method for scalar fields. You would indeed have to manually increase the 'contrast' (by multiplying first by a scale value, and then add an offset - see https://math.stackexchange.com/question ... f-an-image for instance). But clearly, that's not easy to do it since it's not interactive (at least you can use the 'Edit > SF > Show Histogram' tool to try to predict the right values).

Another thing you can also do / play with is the 'min and max saturation' values of the scalar field. They will let you change interactively the mapping between the scalar field values and the false colors (that can help to find the right scale and offset).