tree d338f02b9abdc6331ec503328fcb8665bc1a180c
parent 569d9f69d5dc40d7e7ec6577a48bccda523ff34e
author yjshen <yjshen@google.com> 1581025697 -0800
committer Damon Shen <yjshen@google.com> 1581383971 +0000

Improve temporal filtering with cross-plane info.

Currently, plane-wise temporal filtering strategy filters Y, U, V planes
independently. However, since the motion search used in temporal
filtering is only performed with Y-plane, the information from Y-plane
is more accurate than UV-plane. Accordingly, this CL filters U and V
planes by considering the information from Y-plane. This significantly
improves PSNR on U-plane and V-plane.

NOTE: Whether Y-plane should consider the information from UV-plane, and
whether U and V planes should consider the information from each other
are still worth exploring. Also, when considering the cross-plane
information, whether the weight should be equivalent as that of
self-plane information is another worth-studying problem.

Since plane-wise strategy is only applied to midres and hdres videos,
only results from these two test sets are reported.

Experimental results:

Under Speed-4 (two-pass mode):
        avg PSNR   ovr PSNR     SSIM   PSNR_Y   PSNR_U   PSNR_V
midres    -0.118     -0.088   -0.109   -0.017   -1.002   -0.783
hdres     -0.036     -0.029   -0.014    0.025   -0.520   -0.582

Under Speed-1 (two-pass mode):
        avg PSNR   ovr PSNR     SSIM   PSNR_Y   PSNR_U   PSNR_V
midres    -0.088     -0.090   -0.070   -0.004   -1.007   -0.845
hdres     -0.045     -0.055   -0.056    0.018   -0.511   -0.516

STATS_CHANGED

Change-Id: Ibf268d9a2ddc269e6282ff582582a77dcd244da7