VirtualdubMod's Levels filter

[nicksteel]

Is there an Avisynth equivalent to VirtualdubMod's Levels filter?

[StainlessS]

Closest is the Levels filter. (based on Vdub version)
http://avisynth.org/mediawiki/Levels

[nicksteel]

Thanks.

I interphet this as:

Levels(0, .83333, 255, 0, 255)

[StainlessS]

Thanks.

I interphet this as:

Levels(0, .83333, 255, 0, 255)

Yes, looks correct to me.

EDIT: Not sure if chroma is handled identically between VDUB and Avisynth versions when gamma <> 1.0.

EDIT: Also, assume you are using on a YUV format ie YUY2 or YV12, to match the
"operate in luma instead of RGB".

ConvertToYUY2() or ConvertToYV12(), beforehand.

[TheSkiller]

I think ticking the "Operate in luma instead of RGB" checkbox makes VDub leave the choma alone (well, basically, as that's mathematically not possibe in case of RGB video).

So you would need something like this to mimic it in AviSynth:
MergeLuma(Last, Levels(0,0.83,255, 0,255)) #does not touch chroma

[poisondeathray]

I think Didee's YLevels processes luma only as well
http://avisynth.org/mediawiki/Ylevels

[StainlessS]

Also, ColorYUV(Gamma_Y= -43) is equiv to gamma 0.83203125
without touching chroma.