ShowChannels() v0.09 - 15 Jan 2019

[StainlessS]

Easiest, as in crop(36,36,-36,-36)

or

x=36
y=36
w=-36
h=-36

[Danette]

Originally Posted by StainlessS

Easiest, as in crop(36,36,-36,-36)

or

x=36
y=36
w=-36
h=-36

Ahhhh, yes ...thanks.

[Dogway]

I noticed that the global variables are one frame late to current frame:

ShowChannels(SetVar=True,show=true)
scriptclip("""subtitle(string(SC_Min_0))""")

It also would be great to support HBD, 1/256 value jump is noticeable when doing levels or some sort of manipulation. Maybe an additional feature would be to flush values (maybe a third column) after a scene change. And support frameprops(?)

[Gavino]

Originally Posted by Dogway

I noticed that the global variables are one frame late to current frame:

ShowChannels(SetVar=True,show=true)
scriptclip("""subtitle(string(SC_Min_0))""")

You need to use ScriptClip(..., after_frame=true) so that the value is evaluated after the frame has been fetched from the filter above.

[StainlessS]

Thanks G.

It also would be great

Baring it in mind.

[Dogway]

Thanks Gavino! I'm making a soft limiter so I was thinking on feeding the (accumulated) loose minmax values, not sure how I can do it without HBD support, somehow I need to force the ShowChannels() call despite not using its output clip.
ColorYUV() has HBD support but didn't see how to extract values. I also want to add a per scene accumulated, a fast method is to reinitiate ShowChannels() after a scene change.


EDIT: Strange, new ScriptClip can't grab ShowChannels globals.

ShowChannels(SetVar=True,show=false)
ScriptClip( function [] () {
propSetArray("_YMin", function[]() { return [SC_Min_0,SC_Max_0] } )
}, after_frame=True )
 propshow()

[StainlessS]

EDIT: ShowChannels SC_LMn_0 and SC_LMx_0 are LOOSE min and max.

You can also use YPlaneMin(Threshold=0.0) and YPlaneMax(Threshold=0.0) for Ymin and Ymax.
YPlaneMin(Threshold=whatever%) and YPlaneMax(Threshold=whatever%) for loose min/max,
if not interested in other values. (and builtin HBD)


EDIT: ShowChannels defo sets Globals [some of my plugs set locals because of some problem/request or other reported by user].

EDIT: I have no idea what your script snippet does, I have not yet figured out that scriptclip function stuff.
But, does this work

ScriptClip( function [] () {
propSetArray("_YMin", function[]() { return [YPlaneMin(0.0),YPlaneMax(0.0)] } )
}, after_frame=True )     # Maybe After_Frame not needed : Presumably YPlaneMin/Max will be using implicit Last (or something ???)
 propshow()

[Dogway]

Yes, maybe I will do that for not accumulated, although that uses 0.4 percentile (?)
I wanted some kind of temporal average for the values.
I managed somewhat to pass the global vars to SoftLimiter, but with the old ScriptClip.

[StainlessS]

ColorYUV(analyse=true)
uses 0.4, actually total Y sample count / 256 for Y, and total Y sample count / 1024 for U and V (when YV12, so still 0.4).
[old v2.58 ColorYUV which I have source for].
ShowChannels uses default 0.1%.

Originally Posted by StainlessS

Loose minimum uses the filter arg float MinPerc, a percentage of total pixels to ignore
when finding the loose minimum, allows to ignore extreme stray pixels.

Loose maximum uses the filter arg float MaxPerc, a percentage of total pixels to ignore
when finding the loose maximum, allows to ignore extreme stray pixels.

Same as loose minimum/maximum in ColorYUV Analyze=true

analyze can be true or false. This will print out color statistics on the screen. 
There are maximum and minimum values for all channels. 
There is an average for all channels.
There is a "loose maximum" and "loose minimum". The "loose" values are made to filter out very bright
or very dark noise creating an artificially low or high minimum / maximum.

Originally Posted by StainlessS

YPlaneMin/YPlaneMax has the same sort of thing where what I've called 'MinPerc/MaxPerc' uses name of 'Threshold'.

YPlaneMin   |   v2.x   |   YPlaneMin(clip, float threshold) 
YPlaneMax   |   v2.x   |   YPlaneMax(clip, float threshold) 

threshold is a percentage, stating how many percent of the pixels are allowed above or below minimum.
The threshold is optional and defaults to 0.

# ...

Comment From ColorYUV source

 // When 1/256th of all pixels have been reached, trigger "Loose min/max"

So ColorYUV ignores 1/256 of the darkest/lightest pixels, YPlaneMin ignores 0% default, and ShowChannels 0.1% or 1/1000 by default,
so a Minperc/Maxperc of 0.4% would be about the same as ColorYUV uses.

EDIT: Should it matter that TV levels range is 220 [not 256] ie 235-16+1, where is 1/220*100 = 0.45454 %.