A Comprehensive Study and Comparison of Core Technologies for MPEG 3-D Point Cloud Compression

Abstract

Point cloud based 3D visual representation is becoming popular due to its ability to exhibit the real world in a more comprehensive and immersive way. However, under a limited network bandwidth, it is very challenging to communicate this kind of media due to its huge data volume. Therefore, the MPEG have launched the standardization for point cloud compression (PCC), and proposed three model categories, i.e., TMC1, TMC2, and TMC3. Because the 3D geometry compression methods of TMC1 and TMC3 are similar, TMC1 and TMC3 are further merged into a new platform namely TMC13. In this paper, we first introduce some basic technologies that are usually used in 3D point cloud compression, then review the encoder architectures of these test models in detail, and finally analyze their rate distortion performance as well as complexity quantitatively for different cases (i.e., lossless geometry and lossless color, lossless geometry and lossy color, lossy geometry and lossy color) by using 16 benchmark 3D point clouds that are recommended by MPEG. Experimental results demonstrate that the coding efficiency of TMC2 is the best on average (especially for lossy geometry and lossy color compression) for dense point clouds while TMC13 achieves the optimal coding performance for sparse and noisy point clouds with lower time complexity.

Hierarchical Bit-Wise Differential Coding (HBDC) of Point Cloud Attributes

“…1 that TM-C13 (the LoD encoder without LT) costs less bits in both geometry coding and color coding, and takes much less time for the encoding than TMC2. Thus, TMC13 is more suitable for lossless point cloud compression than TMC2 [20]. Further, we observe from Tab.…”

“…We provide in Tab. 1 the bitrate and time statistics of HB-DC, TMC13 and TMC2, with the numbers for TMC13 and TMC2 extracted from the work of Liu et al [20] where reference software V11.0 and V9.0 are used for TMC13 and TM-C2, respectively, and the configuration of the common test condition (CTC) is used. It is observed from Tab.…”

“…TMC1 and TMC3 codecs were further combined into a new platform, TMC13. These test models are viewed as the state-of-the-art benchmarks and evaluated in full length in recent works [19,20].…”

“…Before coding, we convert the color attribute from the RGB format to the YU-V format. We compare our proposed point cloud codec with TMC13 and TMC2 under Case 1 where both geometry and color are compressed losslessly [20]. The performance metrics include bitrate in bits per point (bpp), encoding time in second (s) and decoding time in second (s).…”

Estudo de Perdas para Codificação de Geometria de Nuvens de Pontos por Decomposição Diádica

“…O MPEG G-PCC TMC13 v7.0 [16] é um codec baseado em geometria que originou das atuais propostas pelo grupo MPEG. Em adição à compressão de geometria sem perdas, o codificador TMC13 possui dois métodos para comprimir a geometria com perdas [17]. O primeiro é uma quantização direta da geometria, a qual será referida nesse trabalho como TMC13 Octree.…”