Noise removel in laidar data

I have a Lidar data in .las file and i want to remove Noise from IT ? is this is possible in open sources tools i.e las tool ,LibLas or any other open source , Because my finding are we can achieve this in point cloud library using .pcd file format But can we do same in Lib las or las tools

It's not clear, from the question, if you need to perform noise removal programmatically or through a tool. Let's try to break down your problem anyway. The point-cloud-library has a nice set of features to perform noise reduction and removal. However, as you noticed, it mainly works on pcl files. You have a couple of options to convert your las files to pcl:

1. You can add this set of readers to your PCL-based project. The LAS reader seems to be able to read las files.
2. You can use the PDAL toolchain, and do something like pdal translate original.las output.pcd.

For the noise removal part you also have a couple of options, once you have the files: you can either either use one of the many noise removal filters from PCL (see here and here, e.g. StatisticalOutlierRemoval) by calling the related classes in your code, or simply use the PDAL processing pipeline from the command line to further clean your data, as described in one of their tutorials.