New release
https://github.com/DTL2020/mvtools/r.../r.2.7.46-a.18
Added SSIM metric in MAnalyse and MPB MDegrainN processing. Now possible dissimilarity metric flags (as bit mask):
bit 0 - SAD,
bit 1 - SSIM luma only,
bit 2 - SSIM contrast and structure.
Examples:
SAD only = 1
SSIM luma only = 2
SSIM contrast and structure = 4
Full (standard) SSIM = 6
SAD + SSIM contrast and structure = 5
Selecting of dissimilarity metric supported only in part of optSearchOptions and optPredictorType of MAnalyse. For example optSearchOption=2 have hardcoded SAD in SIMD and can not be switched.
New param for MDegrainN - MPB_DMFlags. Integer any of dissimilarity metric bitmask, default=1.
New param for MAnalyse - DMFlags Integer any of dissimilarity metric bitmask, default=1.
New param for MRecalculate - DMFlags Integer any of dissimilarity metric bitmask, default=1.
Current release have only C-reference partially float32 SSIM calculation functions (best precision and support all blocksizes and bithdepths) so very slow. For quality check mostly. Current processing speed degradation of MDegrainN MPB using SSIM about 2 times. MAnalyse usiing SSIM about 4 times. Expected good benefit from SIMD versions in the future (for some limited number of block sizes and bitdepths).
Example of interleaved frames with different dissimilarity metric for MPB processing:
Code:
ssim=MDegrainN(last,super, multi_vec, tr, thSAD=250, thSAD2=240, thSADC=240, mt=false, wpow=4, thSCD1=400, adjSADzeromv=0.5, adjSADcohmv=0.5, thCohMV=16, MVLPFGauss=0.9, thMVLPFCorr=50,
UseSubShift=1, IntOvlp=3, MPBthSub=2, MPBthAdd=2000, MPBNumIt=2, MPB_SPCadd=1.5, MPB_SPCsub=0.6, MPBthIVS=1500, showIVSmask=false, MPB_DMFlags=6).Subtitle("SSIM")
sad=MDegrainN(last,super, multi_vec, tr, thSAD=250, thSAD2=240, thSADC=240, mt=false, wpow=4, thSCD1=400, adjSADzeromv=0.5, adjSADcohmv=0.5, thCohMV=16, MVLPFGauss=0.9, thMVLPFCorr=50,
UseSubShift=1, IntOvlp=3, MPBthSub=2, MPBthAdd=2000, MPBNumIt=2, MPB_SPCadd=1.5, MPB_SPCsub=0.6, MPBthIVS=1500, showIVSmask=false, MPB_DMFlags=1).Subtitle("SAD")
Interleave(ssim, sad)
The SSIM metric produce much more great deviation of metric value so if using in MAnalyse and MDegrain the thSCD1 param of MDegrain must be significantly adjusted to higher value (like from 400 to 15000 or higher). Check MShow mean-SAD output to see expected value. Though thSAD can be about the same as with SAD metric.
Combinations of SAD+SSIM is additive (so thSAD may be about 2 times higher if used).
Combinations of SSIM-luma and SSIM-contrast and structure are multiplied (to form 'standard SSIM'). So enabling standard SSIM may not require significant thSAD adjustment.
Current conversion of SSIM into something close to SAD computing engine:
Dissimilarity metric = (1-SSIM) * maxSAD/2.
Where maxSAD = (3 * nBlkSizeX * nBlkSizeY * (pixelsize == 4 ? 1 : (1 << nBPP)))
So -2 SSIM (totally different blocks) shoud reach maxSAD. Though it looks the intermediate values of SAD and SSIM with some intermediate blocks dissimilarities are very different. May be it good to add some power-function to align a bit better in the future. Though the much higher gain of SSIM around low SAD may helps to MDegrainN and MVs search better.
Expected other metrics for addition in the future like CW-SSIM and others. Currently new intermediate helper class DisMetric is used so addition of new metrics is now much easier. Though the new class add some overhead at calling of metric function and selection so performance of SAD only metric may be visibly degradred.