Alpha channel handling in PointCloudColorHandler

[nizar-sallem]

Hi,

Seems that we don't handle the alpha channel in the PointCloudColorHandler.
After a bit of investigation it appears we only use the RGB data to build the scalars.
I would suggest that we create a specialization for the pcl::PointXYZRGBA at least where the alpha is handled correctly. Of course we would need to modify the default constructor of pcl::PointXYZRGBA accordingly so that every point is opaque to start with or else we would have to add an alpha capable color handler (my preference goes for this one as I think the PCD file are saved from kinect and so on with alpha set to 0 which would lead to black point clouds I am afraid but didn't experiment that yet).

What do you think ? @jspricke @rbrusu

[jspricke]

+1 from me, @nizar-sallem did you have a look at the black cloud already? Also, you can upgrade an issue to a pull request using http://hub.github.com/. Would be great if you could use this instead of opening two bugs for the same thing. Thanks!

[nizar-sallem]

Hi Jochen I did that and sent the pull request already, as it is referenced this one will be closed once the pull request is merged.
The black cloud is fixed in the pull request as well by setting a to 255 in the default PointXYZRGBA constructor.