MysteryX
7th June 2016, 06:52
One thing that I'm not seeing much in AviSynth is ringing cancellation after resize. Yet I'm sure there are various people who have done it in various ways. Also, I see this wasn't implemented in MPDN either.
What are ways to do ringing-cancellation?
The only one I found is the one that comes with DitherTools. Is this a good approach or are there better ways to do it?
Function Dither_resize16nr (clip src, int width, int height,
\ float "src_left",
\ float "src_top",
\ float "src_width",
\ float "src_height",
\ string "kernel",
\ float "fh",
\ float "fv",
\ int "taps",
\ float "a1",
\ float "a2",
\ float "a3",
\ int "kovrspl",
\ bool "cnorm",
\ bool "center",
\ string "cplace",
\ int "y",
\ int "u",
\ int "v",
\ string "kernelh",
\ string "kernelv",
\ float "totalh",
\ float "totalv",
\ bool "invks",
\ bool "invksh",
\ bool "invksv",
\ int "invkstaps",
\ string "cplaces",
\ string "cplaced",
\ string "csp",
\ bool "noring")
{
noring = Default (noring, true)
Assert (width > 0 && height > 0, "Dither_resize16nr: width and height must be > 0.")
sr_h = Float (width ) / Float (src.width () )
sr_v = Float (height) / Float (src.height ())
sr_up = Dither_max (sr_h, sr_v)
sr_dw = 1.0 / Dither_min (sr_h, sr_v)
sr = Dither_max (sr_up, sr_dw)
Assert (sr >= 1.0)
# Depending on the scale ratio, we may blend or totally disable
# the ringing cancellation
thr = 2.5
nrb = (sr > thr)
nrf = (sr < thr + 1.0 && noring)
nrr = (nrb) ? Dither_min (sr - thr, 1.0) : 1.0
nrv = (nrb) ? Round ((1.0 - nrr) * 255) * $010101 : 0
main = src.Dither_resize16 (width, height,
\ src_left =src_left,
\ src_top =src_top,
\ src_width =src_width,
\ src_height=src_height,
\ kernel =kernel,
\ fh =fh,
\ fv =fv,
\ taps =taps,
\ a1 =a1,
\ a2 =a2,
\ a3 =a3,
\ kovrspl =kovrspl,
\ cnorm =cnorm,
\ center =center,
\ cplace =cplace,
\ y =y,
\ u =u,
\ v =v,
\ kernelh =kernelh,
\ kernelv =kernelv,
\ totalh =totalh,
\ totalv =totalv,
\ invks =invks,
\ invksh =invksh,
\ invksv =invksv,
\ invkstaps =invkstaps,
\ cplaces =cplaces,
\ cplaced =cplaced,
\ csp =csp
\ )
nrng = (nrf) ? src.Dither_resize16 (width, height,
\ src_left =src_left,
\ src_top =src_top,
\ src_width =src_width,
\ src_height=src_height,
\ kernel ="gauss",
\ a1 =100,
\ center =center,
\ cplace =cplace,
\ cplaces =cplaces,
\ cplaced =cplaced,
\ csp =csp,
\ y =y,
\ u =u,
\ v =v
\ ) : main
nrm = (nrb && nrf) ? main.BlankClip (color_yuv=nrv, height=main.Height()/2) : main
# To do: use a simple frame blending instead of Dither_merge16
rgm = 1
rgc = (nrb) ? -1 : 0
rgy = Defined (y) ? ((y == 3) ? rgm : rgc) : rgm
rgu = Defined (u) ? ((u == 3) ? rgm : rgc) : rgm
rgv = Defined (v) ? ((v == 3) ? rgm : rgc) : rgm
rguv = Dither_max (rgu, rgv)
(nrf ) ? main.Dither_repair16 (nrng, rgy, rguv) : main
(nrf && nrb) ? Dither_merge16_8 (main, last, nrm, y=y, u=u, v=v) : last
}
What are ways to do ringing-cancellation?
The only one I found is the one that comes with DitherTools. Is this a good approach or are there better ways to do it?
Function Dither_resize16nr (clip src, int width, int height,
\ float "src_left",
\ float "src_top",
\ float "src_width",
\ float "src_height",
\ string "kernel",
\ float "fh",
\ float "fv",
\ int "taps",
\ float "a1",
\ float "a2",
\ float "a3",
\ int "kovrspl",
\ bool "cnorm",
\ bool "center",
\ string "cplace",
\ int "y",
\ int "u",
\ int "v",
\ string "kernelh",
\ string "kernelv",
\ float "totalh",
\ float "totalv",
\ bool "invks",
\ bool "invksh",
\ bool "invksv",
\ int "invkstaps",
\ string "cplaces",
\ string "cplaced",
\ string "csp",
\ bool "noring")
{
noring = Default (noring, true)
Assert (width > 0 && height > 0, "Dither_resize16nr: width and height must be > 0.")
sr_h = Float (width ) / Float (src.width () )
sr_v = Float (height) / Float (src.height ())
sr_up = Dither_max (sr_h, sr_v)
sr_dw = 1.0 / Dither_min (sr_h, sr_v)
sr = Dither_max (sr_up, sr_dw)
Assert (sr >= 1.0)
# Depending on the scale ratio, we may blend or totally disable
# the ringing cancellation
thr = 2.5
nrb = (sr > thr)
nrf = (sr < thr + 1.0 && noring)
nrr = (nrb) ? Dither_min (sr - thr, 1.0) : 1.0
nrv = (nrb) ? Round ((1.0 - nrr) * 255) * $010101 : 0
main = src.Dither_resize16 (width, height,
\ src_left =src_left,
\ src_top =src_top,
\ src_width =src_width,
\ src_height=src_height,
\ kernel =kernel,
\ fh =fh,
\ fv =fv,
\ taps =taps,
\ a1 =a1,
\ a2 =a2,
\ a3 =a3,
\ kovrspl =kovrspl,
\ cnorm =cnorm,
\ center =center,
\ cplace =cplace,
\ y =y,
\ u =u,
\ v =v,
\ kernelh =kernelh,
\ kernelv =kernelv,
\ totalh =totalh,
\ totalv =totalv,
\ invks =invks,
\ invksh =invksh,
\ invksv =invksv,
\ invkstaps =invkstaps,
\ cplaces =cplaces,
\ cplaced =cplaced,
\ csp =csp
\ )
nrng = (nrf) ? src.Dither_resize16 (width, height,
\ src_left =src_left,
\ src_top =src_top,
\ src_width =src_width,
\ src_height=src_height,
\ kernel ="gauss",
\ a1 =100,
\ center =center,
\ cplace =cplace,
\ cplaces =cplaces,
\ cplaced =cplaced,
\ csp =csp,
\ y =y,
\ u =u,
\ v =v
\ ) : main
nrm = (nrb && nrf) ? main.BlankClip (color_yuv=nrv, height=main.Height()/2) : main
# To do: use a simple frame blending instead of Dither_merge16
rgm = 1
rgc = (nrb) ? -1 : 0
rgy = Defined (y) ? ((y == 3) ? rgm : rgc) : rgm
rgu = Defined (u) ? ((u == 3) ? rgm : rgc) : rgm
rgv = Defined (v) ? ((v == 3) ? rgm : rgc) : rgm
rguv = Dither_max (rgu, rgv)
(nrf ) ? main.Dither_repair16 (nrng, rgy, rguv) : main
(nrf && nrb) ? Dither_merge16_8 (main, last, nrm, y=y, u=u, v=v) : last
}