Novel Chroma Sampling Methods for CFA Video Compression in AVC, HEVC and VVC

Novel and Optimal Luma Modification-Based Chroma Downsampling for Bayer Color Filter Array Images

“…3) Execution Time Comparison: From the last columns in Table 2, we observe that although our optimal method takes more time (in seconds) than some methods in CD, our optimal method has the best quality and quality-bitrate tradeoff. Furthermore, in Table 4, we observe that not only the quality merit, but our optimal method also has better execution-time performance relative to IDID [26] and JCDU [21]; however, the modified 4:2:0(A) method [14] is faster than ours.…”

“…In CD, 4:2:0(A), 4:2:0(R), 4:2:0(DIRECT) and 4:2:0(MPEG-B) are traditionally used chroma downsampling methods; the BPP, BM, and GD methods are three state-of-the-art chroma downsampling methods with consideration of the input Bayer CFA pattern. In addition, we also introduce the three state-of-theart chroma downsampling methods without considering the input Bayer CFA pattern, namely the interpolation-dependent image downsampling (IDID) method [26], the joint chroma downsampling and upsampling (JCDU) method [21], and the modified 4:2:0(A) method [14].…”

“…Following the same differentiation technique and the COPY-based chroma upsampling process at the server side used in the BM method [13], but without considering the input Bayer CFA pattern, Lin et al [14] proposed a modified 4:2:0(A) chroma downsampling method, and also applied it to the other CFA formats [16], [17], [22] considered in [13]. At the client side, they improved the previous chroma upsampling process [24] by considering the distance between each estimated upsampled chroma value and its three neighboring (TN) pixels; for convenience, their improved chroma upsampling method is called the TN method.…”

Effective Chroma Subsampling and Luma Modification for RGB Full-Color Images Using the Multiple Linear Regression Technique

“…In this subsection, we introduce six traditional chroma subsampling methods and three state-of-the-art chroma subsampling methods [12], [1], [6]. All of them will be included in the comparative methods.…”

“…Lin et al [6] proposed a modified chroma 4:2:0(A) subsampling method, namely modified 4:2:0(A), by considering the truncation and carry operations influence; among the four considered variants, they select the best subsampled (U, V )pair. At the client side, they improved the previous chroma upsampling process [10] by considering the distance between each estimated upsampled chroma value and its three neighboring (TN) pixels; their combination, modified 4:2:0(A)-TN, achieves good quality of the reconstructed RGB fullcolor image.…”