Limiter
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(Difference between revisions)
(Swapped "autoscale" with paramscale which is the right parameter for scaling values automaticaly inside Limiter()) |
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The standard known as Rec.601 or [[Wikipedia:Rec._601|CCIR-601]] (''Studio Encoding Parameters of Digital Television...'') defines standard quantization levels: for luminance, black is '''16''' and peak white is '''235'''. This is the normal luminance range. For chrominance, the range is '''16''' to '''240''', or 128±112. "The signal may occasionally excurse beyond" these ranges according to Rec.601.<sup>[http://www.itu.int/rec/R-REC-BT.601/ BT.601-7] (Annex 1, Table 3)</sup> | The standard known as Rec.601 or [[Wikipedia:Rec._601|CCIR-601]] (''Studio Encoding Parameters of Digital Television...'') defines standard quantization levels: for luminance, black is '''16''' and peak white is '''235'''. This is the normal luminance range. For chrominance, the range is '''16''' to '''240''', or 128±112. "The signal may occasionally excurse beyond" these ranges according to Rec.601.<sup>[http://www.itu.int/rec/R-REC-BT.601/ BT.601-7] (Annex 1, Table 3)</sup> | ||
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'''Limiter''' can also colorize out-of-range pixels (with {{FuncArg|show}}) to warn of a potential problem. See the [[#Examples|example images]] below. Naturally, this option should not be enabled for final output. | '''Limiter''' can also colorize out-of-range pixels (with {{FuncArg|show}}) to warn of a potential problem. See the [[#Examples|example images]] below. Naturally, this option should not be enabled for final output. | ||
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| + | {{AvsPluscon}} By default all parameters are ''non''-[[Autoscale_parameter|autoscaling]] – they must be scaled to the target bit depth.<br> | ||
| + | By using parameter ''paramscale'' the range parameters are treated to be of 8 bits range and will be scaled to the current bit depth automatically | ||
| + | </div> | ||
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__TOC__ | __TOC__ | ||
== Syntax and Parameters == | == Syntax and Parameters == | ||
| + | <div style="max-width:62em" > | ||
{{Template:FuncDef | {{Template:FuncDef | ||
| − | |Limiter(clip ''clip'' [, int ''min_luma'', int ''max_luma'', int ''min_chroma'', int ''max_chroma'', string show ] ) | + | |Limiter(clip ''clip'' [, int ''min_luma'', int ''max_luma'', int ''min_chroma'', int ''max_chroma'', string ''show'' ] ) |
| + | }} | ||
| + | <br>{{Template:FuncDef | ||
| + | |{{AvsPluscon}} Limiter(clip ''clip'' [, float ''min_luma'', float ''max_luma'', float ''min_chroma'', float ''max_chroma'', string ''show'', bool ''paramscale'' ] ) | ||
}} | }} | ||
:{{Par2|clip|clip|(required)}} | :{{Par2|clip|clip|(required)}} | ||
::Source clip. [[YUV]] only. | ::Source clip. [[YUV]] only. | ||
| + | ::{{AvsPluscon}} also supports [[YUVA]]. | ||
| − | :{{Par2|min_luma|int|16}} | + | :{{Par2|min_luma|int|16{{Template:D}}}} |
::''Y'' (luma) lower bound. | ::''Y'' (luma) lower bound. | ||
| − | :{{Par2|max_luma|int|235}} | + | :{{Par2|max_luma|int|235{{Template:D}}}} |
::''Y'' (luma) upper bound. | ::''Y'' (luma) upper bound. | ||
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::''U'' & ''V'' (chroma) lower bound. | ::''U'' & ''V'' (chroma) lower bound. | ||
| − | :{{Par2|max_chroma|int|240}} | + | :{{Par2|max_chroma|int|240{{Template:D}}}} |
::''U'' & ''V'' (chroma) upper bound. | ::''U'' & ''V'' (chroma) upper bound. | ||
| Line 99: | Line 110: | ||
| {{BoldColor|#FF00FF|120|♦}} magenta | | {{BoldColor|#FF00FF|120|♦}} magenta | ||
|} | |} | ||
| + | </div> | ||
| + | |||
| + | :{{AvsPluscon}} {{Par2|paramscale|bool|false}} | ||
| + | :: If set, minimum/maximum luma/chroma values are treated as they were in 8 bit range (but non-integer values are allowed), limiter will autoscale them to the current bit depth of the clip. | ||
| + | :: Conversion uses the bit-shift method for integer bit depth conversion (from 8 to 8-16 bits). For 32 bit float clips the conversion is value/255.0 for Y (luma) channel and (value-128)/255.0 for U/V chroma channels. Do not use paramscale when you want to limit 32 bit float chroma exactly to +/-0.5, give the parameters directly instead. | ||
| + | ::Default: does not scale at all, parameters are used as-is. Parameters now are of float type to handle 32 bit float values.. | ||
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[[FFmpegSource|FFmpegSource2]]("[http://www.sintel.org/ sintel].mp4") | [[FFmpegSource|FFmpegSource2]]("[http://www.sintel.org/ sintel].mp4") | ||
[[Trim]](4685, 4685) | [[Trim]](4685, 4685) | ||
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# 2. Exaggerated luma and chroma range | # 2. Exaggerated luma and chroma range | ||
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[[Levels]](16, 1.0, 255-16, 0, 255, coring=false) | [[Levels]](16, 1.0, 255-16, 0, 255, coring=false) | ||
[[Tweak]](sat=2.0, coring=false) | [[Tweak]](sat=2.0, coring=false) | ||
| + | # (''insert Limiter here'') | ||
ColorYUV(analyze=true) | ColorYUV(analyze=true) | ||
|- | |- | ||
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|[[File:Limit_Ex07a.png|768px]] | |[[File:Limit_Ex07a.png|768px]] | ||
|} | |} | ||
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== Changes == | == Changes == | ||
{| border="1" | {| border="1" | ||
| + | |- | ||
| + | | {{AvsPluscon}} r2724 | ||
| + | | Added support for float. | ||
| + | Added ''paramscale'' | ||
| + | |- | ||
| + | | {{AvsPluscon}} | ||
| + | | Added support for 8-16bit color spaces. | ||
|- | |- | ||
| v2.60 | | v2.60 | ||
Latest revision as of 14:15, 25 September 2020
The standard known as Rec.601 or CCIR-601 (Studio Encoding Parameters of Digital Television...) defines standard quantization levels: for luminance, black is 16 and peak white is 235. This is the normal luminance range. For chrominance, the range is 16 to 240, or 128±112. "The signal may occasionally excurse beyond" these ranges according to Rec.601.BT.601-7 (Annex 1, Table 3)
Luminance or chrominance values outside their ranges are known to cause problems with some TV sets, so Limiter was created to clip them (or clamp them - both terms are used) to the ranges [min_luma, max_luma] and [min_chroma, max_chroma], which you may specify, but by default are the Rec.601 values listed above.
Limiter can also colorize out-of-range pixels (with show) to warn of a potential problem. See the example images below. Naturally, this option should not be enabled for final output.
AVS+ By default all parameters are non-autoscaling – they must be scaled to the target bit depth.
By using parameter paramscale the range parameters are treated to be of 8 bits range and will be scaled to the current bit depth automatically
Contents |
[edit] Syntax and Parameters
Limiter(clip clip [, int min_luma, int max_luma, int min_chroma, int max_chroma, string show ] )
AVS+ Limiter(clip clip [, float min_luma, float max_luma, float min_chroma, float max_chroma, string show, bool paramscale ] )
- int min_luma = 16d
- Y (luma) lower bound.
- int max_luma = 235d
- Y (luma) upper bound.
- int min_chroma = 16
- U & V (chroma) lower bound.
- int max_chroma = 240d
- U & V (chroma) upper bound.
- string show = (empty)
- Colorizes the pixels outside the specified [min_X, max_X] range.
- If set, show must take one of the following values:
show Effect "luma" colorizes out of bound luma "luma_grey" colorizes out of bound luma, and makes the remaining pixels grey "chroma" colorizes out of bound chroma "chroma_grey" colorizes out of bound chroma, and makes the remaining pixels grey
Pixel Condition Colorization show="luma" show="luma_grey" Yj < min_luma ♦ red (pj) ♦ red (pj) Yj > max_luma ♦ green (pj) ♦ green (pj) Yj < min_luma and Yk > max_luma ♦ yellow (pj and pk) ♦ puke (pj) ♦ olive (pk) show="chroma" show="chroma_grey" U < min_chroma ♦ yellow ♦ yellow U > max_chroma ♦ blue V < min_chroma ♦ cyan V > max_chroma ♦ red U < min_chroma and V < min_chroma ♦ green U > max_chroma and V < min_chroma ♦ teal U < min_chroma and V > max_chroma ♦ orange U > max_chroma and V > max_chroma ♦ magenta
- AVS+ bool paramscale = false
- If set, minimum/maximum luma/chroma values are treated as they were in 8 bit range (but non-integer values are allowed), limiter will autoscale them to the current bit depth of the clip.
- Conversion uses the bit-shift method for integer bit depth conversion (from 8 to 8-16 bits). For 32 bit float clips the conversion is value/255.0 for Y (luma) channel and (value-128)/255.0 for U/V chroma channels. Do not use paramscale when you want to limit 32 bit float chroma exactly to +/-0.5, give the parameters directly instead.
- Default: does not scale at all, parameters are used as-is. Parameters now are of float type to handle 32 bit float values..
[edit] Examples
# 1. Original image FFmpegSource2("sintel.mp4") Trim(4685, 4685) # 2. Exaggerated luma and chroma range Levels(16, 1.0, 255-16, 0, 255, coring=false) Tweak(sat=2.0, coring=false) # (insert Limiter here) ColorYUV(analyze=true)
# 3. Limiter("luma") [...] Limiter(16, 235, 16, 240, "luma") ColorYUV(analyze=true)
# 4. Limiter("luma_grey") [...] Limiter(16, 235, 16, 240, "luma_grey") ColorYUV(analyze=true)
# 5. Limiter("chroma") [...] Limiter(16, 235, 16, 240, "chroma") ColorYUV(analyze=true)
# 6. Limiter("chroma_grey") [...] Limiter(16, 235, 16, 240, "chroma_grey") ColorYUV(analyze=true)
# 7. Putting it all together [...] StackHorizontal( \ Last \ , StackVertical( \ Histogram("levels", 0.5).Crop(Width, 0, 256, 256).AddBorders(0, 0, 0, Height/2-256) \ , Histogram("color2" ).Crop(Width, 0, 256, 256).AddBorders(0, 0, 0, Height/2-256) \ ) \ , StackVertical( \ BicubicResize(Width/2, Height/2).Limiter(16, 235, 16, 240, "luma_grey") \ , BicubicResize(Width/2, Height/2).Limiter(16, 235, 16, 240, "chroma_grey") \ ) \ )
[edit] Changes
| AVS+ r2724 | Added support for float.
Added paramscale |
| AVS+ | Added support for 8-16bit color spaces. |
| v2.60 | Added support for YV24. |
| v2.56 | Added show to show out of bound luma/chroma. |
