Color vibrance

[Motenai Yoda]

Hi! I'm looking for a simple way to do a color vibrance effect with avisynth, but after searching a little on google I have not found anything.

there is a way to make a saturation mask to merge a saturated clip or apply saturation only where saturation is low?

thanks

[SSH4]

mask:

mt_lut("x 128 - abs 4 *",u=3,v=3).Spline36Resize(width*2,height*2)
mt_lutxy(UtoY(),VtoY(),"x y > x y ?",chroma="128")

play with 4 in first line

[Motenai Yoda]

@SSH4 thanks I'll try
but I'm thinking something like

mask=mt_lutxy(Vtoy(),Utoy(),"x 128 - abs y 128 - abs +").levels(0,1.0,40,0,255,false)
mt_merge(tweak(sat=2.0),last,YToUV(mask,mask),y=4,u=3,v=3)

[Dogway]

Wow very good, I tried to make this a few weeks ago, didn't know it was called Vibrance. In my case I found to make a good range if I multiplied everything by 3.
msk=mt_lutxy(Vtoy(),Utoy(),"x 128 - abs y 128 - abs + 3 *")
Thanks for this!

I'll add it to my mask pack functions if you don't mind.

[SSH4]

first scale x2 than UtoY or VtoY or on mod2 you can catch error.
or *toY(last.scale(x2))

I'm always forgot about this

[Gavino]

Rather than using abs(u-128)+abs(v-128) as a measure of saturation, you could try sqrt((u-128)^2+(v-128)^2) which corresponds more to the 'color circle' viewpoint.

[Didée]

First, though I agree that doing this step-by-step (with masks and filters and chroma-to-luma-and-back and merging and stuff and all and whatnotelse) might be easier to understand while setting-up. But really, you can do it all with 2 mt_lutxy and 1 swapUV().

Second: expsat

And, as a matter of course, LaTo's splendid SmoothAdjust.

[Motenai Yoda]

@Dogway nvidia, ati, and ps call it so
http://www.photo-mark.com/notes/2009...nd-saturation/

@Gavino while I was eating dinner, I saw the bowl and had reached the point. but at the corner isn't 128 is ≈181 i notice that in CIELUV the formula is the same, but 255/255 shouldn't be 128 too?

@Didée I've found a link to a page about brabbudu, but it was broken. For SmoothAdjust that don't know very well, it's work on saturation or on channels? 'Cause with ps in Lab using a S curve on a and b does something similar saturation...
also understand how these things work is my gripe for some time.

now assuming that
U=x and increased_sat_U = x*k
difference between should be (x*k) -x = x*(k-1)
mask is (128 - sqrt((u-128)^2+(v-128)^2))/128, 1 at 0, 0 at 128

so vibrance_U = x+[x*(k-1)*mask] = x * {1 + [(k-1)*mask]}

this

mask=mt_lutxy(UtoY(),VtoY(),"x 128. - 2. ^ y 128. - 2. ^ +  1. 2. / ^ 128 > 0 "+
\+"128. x 128. - 2. ^ y 128. - 2. ^ +  1. 2. / ^ - 128. / "+string(float(g))+" ^ 255. * ? ",u=1,v=1)
mt_lutxy(last,YToUV(mask,mask),"x 128. - y 255. / "+string(float(k-1))+" * 1.0 + * 128. +",y=2,u=3,v=3)

should be right, it isn't?
(g is the gamma of mask)


sorry for the screenshoots but I'haven't nothing free to use
for g=0., k=1.5 it looks very like as tweak(sat=1.5)
edit also is the same as Smoothtweak(saturation=1.5,smooth=200), changing smooth from 0 to 200 don't affect the saturation.

edited as suggested Gavino

mask=mt_lutxy(UtoY(),VtoY(),"x 128 - 2 ^ y 128 - 2 ^ +  .5 ^ 128 > 0 "+
\+"128 x 128 - 2 ^ y 128 - 2 ^ +  .5 ^ - 128 / "+string(g)+" ^ 255 * ? ",u=1,v=1)
mt_lutxy(last,YToUV(mask,mask),"x 128 - y 255 / "+string(k-1)+" * 1 + * 128 +",y=2,u=3,v=3)

[Gavino]

"1. 2. /" can of course be replaced by "0.5".
Also, you don't need to use float literals (eg "128."), since internally masktools treats everything as float (just use "128", it's easier to read).

[joka]

I'am still learning. Sorry for the question. Shouldn't be g=1. In my opinion g=0 (as mentioned for the screen shots) will disable the mask.

[Motenai Yoda]

Originally Posted by joka

I'am still learning. Sorry for the question. Shouldn't be g=1. In my opinion g=0 (as mentioned for the screen shots) will disable the mask.

g=0 don't disable mask at all, 'cause codition
sqrt((u-128)^2+(v-128)^2) < 128 to apply some value of g (ie g=2.) it returns 0 if sqrt((u-128)^2+(v-128)^2) >= 128 instead of negative value, so for high saturated area the mask is always 0 (or 255 depending on your point).

the g & k values should be tuned for different content, anime & cartoon are more saturated than real life content, so g=2. is ok for animation, but for live action higher values works better (about 10 - 20).

also as Didée said (even if with only one mt_lutxy...)

mt_lutxy(last,SwapUV(),"x 128 - 2 ^ y 128 - 2 ^ +  .5 ^ 128 > x "+
\+" x 128 - 128 x 128 - 2 ^ y 128 - 2 ^ +  .5 ^ - 128 / "+string(g)+" ^ "+string(k-1)+
\+" * 1 + * 128 + ?",y=2,u=3,v=3)

[SSH4]

rough code....

a=last
Overlay(Grayscale(),mode="difference")
mt_lutxy(UtoY(Spline64Resize(width*2,height*2)),VtoY(Spline64Resize(width*2,height*2)),"x y > x y ?",chroma="128").ColorYUV(autogain=true,levels="TV->PC").RemoveGrain(12,-1)
mt_merge(a,a.Tweak(sat=3),last,luma=true)
StackHorizontal(a.Tweak(sat=3).Subtitle("Saturaion"),last.Subtitle("Vibrance"))

Source: http://www.digitalphoton.net/color-v...-in-photoshop/

[IanB]

Try Tweak(Sat=1.5, MaxSat=59.5, interp=20)

Increase saturation by 50% when below 59.5, linearly reducing from 50% to 0% over 59.5 up to 79.5. (Peak saturation is 150 tweak units, [R=255,G=B=0] has a saturation of 119 tweak units)

[Motenai Yoda]

@SSH4 It's wrong
- "x y > x y ?", this take only max, but u & v are 128 centered, if u=128 and y=200 it's different from u=199 and y=200...
also u=128 and y=56 instead is the same.
- ColorYUV(autogain=true,levels="TV->PC") , autolevels can be done there for photo content, but is no good for video content.

edit typing error change y with v

[Nevilne]

Color vibrance in photoshop radically changes luma as well by the way.

[SSH4]

Motenai Yoda yep, you right. "x y > x y ? 128 - abs 2 *" is little bit better...
but IanB give better and more native Avisynth way for vibrance.

[IanB]

You probably meant :-

"x 128 - abs y 128 - abs > x y ? 128 - abs"

or better still try

"x 128 - x 128 - * y 128 - y 128 - * + sqrt" # sqrt( (x-128)**2 + (y-128)**2 )

[SSH4]

oops you right.

[Dogway]

function SatMask(clip c, "Sat", float "bias", string "mode", clip "Rc", bool "lsb", bool "show"){

 bias  = string(default(bias, 5))
 mode  = string(default(mode,  "Vibrance"))
 lsb   = default(lsb,  false)
 show  = default(show, false)


lsb ? c.ditherpost(mode=6) : c

 w=width()
 h=height()
 
Assert(isclip(Sat) || isint(Sat) || isfloat(Sat),  "'Sat' only accepts float, integers or clip inputs")
Assert(w%4  == 0, "width and height must be mod 4 resolution")
Assert(h%4  == 0, "width and height must be mod 4 resolution")

fmode = isclip(Sat) ? false : (Sat>0.0 ? true : false)
a=                   mode=="Recover" ? mt_lutxy(Vtoy(Rc),Utoy(Rc),"x 128 - 2 ^ y 128 - 2 ^ +  .5 ^ 128 > 255 x 128 - 2 ^ y 128 - 2 ^ +  .5 ^ "+bias+" * ?",u=1,v=1) : nop
b= !fmode || show || mode=="Recover" ? mt_lutxy(Vtoy(),Utoy(),    "x 128 - 2 ^ y 128 - 2 ^ +  .5 ^ 128 > 255 x 128 - 2 ^ y 128 - 2 ^ +  .5 ^ "+bias+" * ?",u=1,v=1) : nop



msk  = !fmode || show ? ((mode=="Vibrance") ? mt_lutxy(Vtoy(),Utoy(),"x 128 - 2 ^ y 128 - 2 ^ +  .5 ^ 128 > 0 128 x 128 - 2 ^ y 128 - 2 ^ +  .5 ^ - 128 / "+bias+" ^ 255 * ? ",u=1,v=1) : \
                         (mode=="Dullness") ? b                                              : \
                         (mode=="Recover")  ? mt_lutxy(a,b,"x y - abs 2 *",u=-128,v=-128)    : \
                          Assert(false, "Wrong Saturation Mode"))                            : nop
                          
show ? (lsb ? msk.Spline36Resize(w,h).Dither_convert_8_to_16() :\
              msk.Spline36Resize(w,h))                         :\
(Defined(Sat) || fmode  ?                                       \
((mode=="Vibrance") ?  \
       (lsb ? (fmode ? mergeluma(Dither_lutxy8(SwapUV(),"x 128 - 2 ^ y 128 - 2 ^ +  .5 ^ 256 * 32768 > x 256 * "+
                                      \+" x 128 - 128 x 128 - 2 ^ y 128 - 2 ^ +  .5 ^ - 128 / "+bias+" ^ "+string(sat-1)+
                                      \+" * 1 + * 128 + 256 * ?",y=2,u=3,v=3),c)                       :\
                                      Dither_merge16(c,Sat,YToUV(msk,msk).Dither_convert_8_to_16,y=4)) :\
              (fmode ? mt_lutxy(SwapUV(),"x 128 - 2 ^ y 128 - 2 ^ +  .5 ^ 128 > x "+
                                      \+" x 128 - 128 x 128 - 2 ^ y 128 - 2 ^ +  .5 ^ - 128 / "+bias+" ^ "+string(sat-1)+
                                      \+" * 1 + * 128 + ?",y=2,u=3,v=3)                                :\
                                      mt_merge(Sat,YToUV(msk,msk),y=4,u=3,v=3)))                       :\
 (mode=="Dullness") ?  \
       (lsb ? (fmode ? mergeluma(Dither_lutxy8(SwapUV(),"x 128 - 2 ^ y 128 - 2 ^ +  .5 ^  256 * 32768 > x 256 * "+
                                      \+" x 128 - x 128 - 2 ^ y 128 - 2 ^ +  .5 ^ "+string(sat-1)+
                                      \+" * "+bias+" / 1 + / 128 + 256 * ?",y=2,u=3,v=3),c)            :\
                                      Dither_merge16(c,Sat,YToUV(msk,msk).Dither_convert_8_to_16,y=4)) :\
              (fmode ? mt_lutxy(SwapUV(),"x 128 - 2 ^ y 128 - 2 ^ +  .5 ^  128 > x "+
                                      \+" x 128 - x 128 - 2 ^ y 128 - 2 ^ +  .5 ^ "+string(sat-1)+
                                      \+" * "+bias+" / 1 + / 128 + ?",y=2,u=3,v=3)                     :\
                                      mt_merge(Sat,YToUV(msk,msk),y=4,u=3,v=3)))                       :\
 (mode=="Recover")  ?  \
       (lsb ? (fmode ? mergeluma(Dither_lutxy8(SwapUV(),"x 128 - 2 ^ y 128 - 2 ^ +  .5 ^ 256 * 32768 > x 256 * "+
                                      \+" x 128 - 128 x 128 - 2 ^ y 128 - 2 ^ +  .5 ^ - 128 / "+bias+" ^ "+string(sat-1)+
                                      \+" * 1 + * 128 + 256 * ?",y=2,u=3,v=3),c)                       :\
                                      Dither_merge16(c,Sat,YToUV(msk,msk).Dither_convert_8_to_16,y=4)) :\
              (fmode ? mt_lutxy(SwapUV(),"x 128 - 2 ^ y 128 - 2 ^ +  .5 ^ 128 > x "+
                                      \+" x 128 - 128 x 128 - 2 ^ y 128 - 2 ^ +  .5 ^ - 128 / "+bias+" ^ "+string(sat-1)+
                                      \+" * 1 + * 128 + ?",y=2,u=3,v=3)                                :\
                                      mt_merge(Sat,YToUV(msk,msk),y=4,u=3,v=3))): nop ) : c)}

[bcn_246]

VERY nice script DogWay, just a couple of suggestions...

1. Any way to modify it to use SVP for motion detection?
2. Did some testing on various videos, I would think a default bias of say, 10 would be better than 5