• Jean-Marc Valin's avatar
    Removing divisions from od_dir_find8() · 9c48eec7
    Jean-Marc Valin authored
    Instead of dividing the squared partial sums by the number n of pixels in the
    line, we multiply by 840/n, where 840=3*5*7*8. This not only avoids the
    divisions, but it also makes the optimization exact as there is no more
    ntt-short1 resuts:
             MEDIUM (%) HIGH (%)
        PSNR -0.012070 -0.059644
     PSNRHVS -0.016845 -0.020871
        SSIM -0.026984 -0.031257
    FASTSSIM -0.026078 0.414901
    Change-Id: Ie553d5e3a545dee860a00879d724ecfc00f0a974
od_dering.c 12.8 KB