PLEASE I UNDERSTAND THAT ENVI LIDAR WORKS AUTHOMATICALLY IN PROCESSING POINT CLOUDS, BUT WHICH ALGORITMS CAN WE DESCRIBE FOR THE VARIOUS PROCESS LIKE IN POINT CLOUD DETECTION, EXTRACTION AND CLASSIFICATION. I HAVE A LIDAR POINT CLOUD AND I NEED TO KNOW THE ALGORITMS USED FOR ALL THE STAGES OF ITS PROCESSING. AND ARTICLE TO MAKES REFERECE TO IN CASE OF A PUBLICATION