B-plane compression technique for lossless and lossy coding of LAS files

Abstract

In this paper, a new technique called B-plane compression is presented. This technique is used to compress LAS files, producing slightly better overall compression gain than the popular LAZ compression engine. Furthermore, the B-plane compression technique has other advantages. B-plane compression processes each of the ten attributes within the LAS files independently, allowing for parallel processing of LAS files, unlike LAZ which uses the return number and number of return attributes to provide context for compression of X, Y, and intensity attributes. Additionally, B-plane compression processes each attribute in a similar manner, with only minor adjustments to the compression technique for the intensity and return attributes as they are compressed as unsigned integers. All other attributes are compressed with the exact same algorithm. Overall, B-plane compression produces on average 1.48% increased compression gain when compared to LAZ compression for lossless compression of LAS files. Additionally, we introduce a quantization step in the compression of X, Y, Z, and intensity attributes, allowing for lossy compression and large compression gain.