User:Raffriff42/sandbox - Revision history

Raffriff42: clear the page

2016-02-17T10:42:04Z

clear the page

Raffriff42: recopy avsforum post verbatim

2016-02-01T02:31:40Z

recopy avsforum post verbatim

← Older revision		Revision as of 04:31, 1 February 2016
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	<div {{ListItemContinue\|2}} >		<div {{ListItemContinue\|2}} >
	''Note:'' the input argument named {{FuncArg\|taps}} should really be called "lobes". When discussing resizers, "taps" has a different meaning, as described below ~~(the first paragraph concerns <code>[[#LanczosResize\|LanczosResize]](taps=2)</code>)~~:		''Note:'' the input argument named {{FuncArg\|taps}} should really be called "lobes". When discussing resizers, "taps" has a different meaning, as described below:

	<div {{ListItemContinue\|2}} >		<div {{ListItemContinue\|2}} >
	"~~For upsampling (making the image larger), the filter is sized such that the entire equation falls across 4 input samples~~, ~~making it~~ a 4-~~tap filter. It doesn't matter how big the output image is going to be~~ - ~~it's still just 4 taps~~. ~~For downsampling (making the image smaller), the equation is sized so it will fall across~~ 4 destination samples, which obviously are spaced at wider intervals than the source samples. ~~So for downsampling by a factor of 2 (making the image half as big), the filter covers 24=8 input samples, and thus 8 taps~~. ~~For 3x downsampling, you need 34=12 taps, and so forth~~.		"So when people talk about Lanczos2, they mean a 2-lobe Lanczos-windowed sinc function. There are actually 4 lobes -- 2 on each side...

	~~Thus~~ the total number of taps you need for downsampling is the downsampling ratio times the number of lobes (thus '''T'''x downsampling and Lanczos'''k'''Resize results in T2k taps). And practically, one needs to round that up to the next even integer. For upsampling, it's always ~~2*k~~ taps." ~~</div>~~		"For upsampling (making the image larger), the filter is sized such that the entire equation falls across 4 input samples, making it a 4-tap filter. It doesn't matter how big the output image is going to be - it's still just 4 taps. For downsampling (making the image smaller), the equation is sized so it will fall across 4 destination samples, which obviously are spaced at wider intervals than the source samples. So for downsampling by a factor of 2 (making the image half as big), the filter covers 8 input samples, and thus 8 taps. For 3X downsampling, you need 12 taps, and so forth.
	~~Source:~~ [http://www.avsforum.com/forum/26-home-theater-computers/460922-lanczos-vs-bicubic-comparison-2.html#post4760581 avsforum post] ([[lanczos lobs/taps\|mirror]]).
			"The total number of taps you need for downsampling is the downsampling ratio times the number of lobes, times 2. And practically, one needs to round that up to the next even integer. For upsampling, it's always 4 taps."

			[http://www.avsforum.com/forum/26-home-theater-computers/460922-lanczos-vs-bicubic-comparison-2.html#post4760581 Don Munsil (avsforum post)] \| [[lanczos lobs/taps\|mirror]].
			</div>
	</div>		</div>
	</div>		</div>

Raffriff42: tweak

2016-02-01T02:21:00Z

tweak

← Older revision		Revision as of 04:21, 1 February 2016
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	----		----
	<div style="max-width:62em" >		<div style="max-width:62em" >
	~~Rescales~~ the input video frames to an arbitrary new resolution, and optionally crops the frame before resizing with sub-pixel precision. There are trade-offs to be considered between ~~retention~~ of detail and ~~introduction of new~~ artifacts~~; this is why there are so many resizers in AviSynth~~.		Scales the input video frames to an arbitrary new resolution, and optionally crops the frame before resizing with sub-pixel precision.

			There are trade-offs to be considered between preservation (or augmentation) of image detail and possible artifacts (i.e., oversharpening).
	</div>		</div>
	__TOC__		__TOC__
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	</div>		</div>

	~~<div {{ListItemContinue}} >~~		*Note the cropping parameters are all [[Script_variables\|floating point]]. This allows any '''Resize''' filter to be used as a sub-pixel shifter. <sup>[http://forum.doom9.org/showpost.php?p=938102&postcount=2]</sup>
	Note the ~~edge semantics~~ are ~~slightly different. Also note that~~ [[~~Crop~~]] ~~gives~~ a ~~hard absolute boundary, and the Resizer filter lobes extend into the cropped region~~ &~~ndash; but not beyond the physical edge of the image.~~

	~~As a general rule, use Crop to remove any hard borders or~~ [[~~Wikipedia:VHS\|VHS~~]] ~~head switching noise; using~~ the ~~Resizer cropping may propagate~~ the ~~noise into~~ the ~~adjacent output pixels. Use~~ the ~~Resizer cropping to maintain accurate~~ edge ~~rendering when excising a part~~ of ~~a complete~~ image.		*Note that [[Crop]] gives a hard boundary, whereas the '''Resize''' filters interpolate pixels outside the cropped region – depending on the resizer kernel – bilinear, bicubic etc, and not beyond the edge of the image.

	~~Note the source cropping parameters are all~~ [[~~Script_variables\|floating point~~]]. ~~This allows any resizer~~ to ~~be used as~~ a ~~sub-pixel shifter~~. ~~<sup>[http://forum.doom9.org/showpost.php?p=938102&postcount=2]</sup>~~		*As a general rule,
	~~</div>~~		** [[Crop]] any hard borders or noise; '''Resize''' cropping may propagate the noise into the output.
			** Use '''Resize''' cropping to maintain accurate edge rendering when excising a part of a complete image.
	</div>		</div>

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	}}		}}

	'''GaussResize''' uses a [[Wikipedia:Gaussian_filter\|gaussian]] resizer, which does not overshoot – ~~making it more accurate,~~ but perhaps not as sharp to the eye.		'''GaussResize''' uses a [[Wikipedia:Gaussian_filter\|gaussian]] resizer, which unlike the bicubics, does not overshoot – but perhaps does not appear as sharp to the eye.

	==== parameter ''p'' ====		==== parameter ''p'' ====
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	}}		}}

	'''Spline16Resize''', '''Spline36Resize''' and '''Spline64Resize''' are three [[Wikipedia:Spline_interpolation\|Spline based]] resizers. They are the (cubic) spline based resizers from [http://sourceforge.net/projects/panotools/ Panorama tools] that fit a spline through the sample points and then derives the filter kernel from the resulting blending polynomials. See [http://forum.doom9.org/showthread.php?t=147117 this thread] for the details.		'''Spline16Resize''', '''Spline36Resize''' and '''Spline64Resize''' are three [[Wikipedia:Spline_interpolation\|Spline based]] resizers. They are the (cubic) spline based resizers from [http://sourceforge.net/projects/panotools/ Panorama tools] that fit a spline through the sample points and then derives the filter kernel from the resulting blending polynomials. See [http://forum.doom9.org/showthread.php?t=147117 this thread] for the technical details.

			The rationale for '''Spline''' is to be as sharp as possible with less ringing artifacts than [[#LanczosResize\|LanczosResize]] produces. '''Spline16Resize''' uses <tt>sqrt(16)=4</tt> sample points, '''Spline36Resize''' uses 6 sample points, etc ... The more sample points used, the sharper your clip will get. Several resizer comparison pages are given in the [[#External Links\|External Links]] section.

	~~The rationale for~~ '''~~Spline~~''' is ~~to be as sharp as possible with~~ less ~~ringing artifacts~~ than ~~[[#LanczosResize\|LanczosResize]] produces~~. '''Spline16Resize''' ~~uses <tt>sqrt(16)=4</tt> sample points~~, '''Spline36Resize''' ~~uses 6 sample points, etc ... The more sample points used, the sharper your clip will get. Several resizer comparison pages are given~~ in the ~~[[#External Links\|External Links]] section~~.		*'''Spline64Resize''' is considered the most accurate filter for enlarging or reducing by moderate amounts (less than double/half).
			*'''Spline16Resize''' is sharper and [[Wikipedia:Ringing_artifacts\|rings]] just a bit, which may be desirable with soft sources.
			*'''Spline36Resize''' is somewhere in between the other two.
	</div>		</div>

Raffriff42: tweak

2016-02-01T01:51:40Z

tweak

← Older revision		Revision as of 03:51, 1 February 2016
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	...or more succinctly:		...or more succinctly:
	</div>		</div>
	<div {{BoxWidthIndent\|36\|3}} >		<div {{BoxWidthIndent\|54\|3}} >
	BilinearResize(100, 150, 10, 10, 200, 300)		BilinearResize(100, 150, 10, 10, 200, 300)
	</div><div {{ListItemContinue}} >		</div><div {{ListItemContinue}} >
	The operations are the same as if you put [[Crop]] before the Resize:		The operations are the same as if you put [[Crop]] before the Resize:
	</div>		</div>
	<div {{BoxWidthIndent\|36\|3}} >		<div {{BoxWidthIndent\|54\|3}} >
	Crop(10, 10, 200, 300).BilinearResize(100, 150)		Crop(10, 10, 200, 300).BilinearResize(100, 150)
	</div>		</div>

Raffriff42: tweak

2016-02-01T01:47:44Z

tweak

← Older revision		Revision as of 03:47, 1 February 2016
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	* If <= zero, they set the cropping of the '''right''' and '''bottom''' edges respectively, before resizing.		* If <= zero, they set the cropping of the '''right''' and '''bottom''' edges respectively, before resizing.
	Note, there are certain limits:		Note, there are certain limits:
	* {{FuncArg\|clip}}.[[Clip_properties\|Width]] must be >= ({{FuncArg\|src_left}} + ~~{{FuncArg\|src_width}}~~)		* {{FuncArg\|clip}}.[[Clip_properties\|Width]] must be >= ({{FuncArg\|src_left}} + '''width''')
	* {{FuncArg\|clip}}.[[Clip_properties\|Width]] must be >  ({{FuncArg\|src_left}} + '''right''')		* {{FuncArg\|clip}}.[[Clip_properties\|Width]] must be >  ({{FuncArg\|src_left}} + '''right''')
	* {{FuncArg\|clip}}.[[Clip_properties\|Height]] must be >= ({{FuncArg\|src_top}} + ~~{{FuncArg\|src_height}}~~)		* {{FuncArg\|clip}}.[[Clip_properties\|Height]] must be >= ({{FuncArg\|src_top}} + '''height''')
	* {{FuncArg\|clip}}.[[Clip_properties\|Height]] must be >  ({{FuncArg\|src_top}} + '''bottom''')		* {{FuncArg\|clip}}.[[Clip_properties\|Height]] must be >  ({{FuncArg\|src_top}} + '''bottom''')
	...otherwise it would enlarge ("un-crop") the clip, or reduce width or height to 0, which is not allowed.		...otherwise it would enlarge ("un-crop") the clip, or reduce width or height to 0, which is not allowed.

Raffriff42: b+2c=1

2016-02-01T01:42:01Z

b+2c=1

← Older revision		Revision as of 03:42, 1 February 2016
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	<div {{ListItemContinue\|2}} >		<div {{ListItemContinue\|2}} >
	You have to set "{{FuncArg\|b}} + 2.0 * {{FuncArg\|c}} = 1~~.0"~~ for the numerically ~~most~~ accurate filter. This gives for {{FuncArg\|b}}=0 the maximum value of 0.5 for {{FuncArg\|c}}, which is the [[Wikipedia:Cubic_Hermite_spline#Catmull.E2.80.93Rom_spline\|Catmull-Rom spline]] and a good suggestion for sharpness.		You have to set [{{FuncArg\|b}} + 2{{FuncArg\|c}} = 1] for the most numerically accurate filter. This gives for {{FuncArg\|b}}=0 the maximum value of 0.5 for {{FuncArg\|c}}, which is the [[Wikipedia:Cubic_Hermite_spline#Catmull.E2.80.93Rom_spline\|Catmull-Rom spline]] and a good suggestion for sharpness.

	As {{FuncArg\|c}} exceeds 0.6, the filter starts to [[Wikipedia:Ringing_artifacts\|"ring"]] or overshoot. You won't get true sharpness – what you'll get is exaggerated edges.		As {{FuncArg\|c}} exceeds 0.6, the filter starts to [[Wikipedia:Ringing_artifacts\|"ring"]] or overshoot. You won't get true sharpness – what you'll get is exaggerated edges.

Raffriff42: typo

2016-02-01T01:35:59Z

typo

← Older revision		Revision as of 03:35, 1 February 2016
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	* {{FuncArg\|clip}}.[[Clip_properties\|Height]] must be >  ({{FuncArg\|src_top}} + '''bottom''')		* {{FuncArg\|clip}}.[[Clip_properties\|Height]] must be >  ({{FuncArg\|src_top}} + '''bottom''')
	...otherwise it would enlarge ("un-crop") the clip, or reduce width or height to 0, which is not allowed.		...otherwise it would enlarge ("un-crop") the clip, or reduce width or height to 0, which is not allowed.
	~~</div>~~
	</div>		</div>

Raffriff42: tweak

2016-02-01T01:27:37Z

tweak

← Older revision		Revision as of 03:27, 1 February 2016
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	* If  > zero, these set the '''width''' and '''height''' of the clip before resizing.		* If  > zero, these set the '''width''' and '''height''' of the clip before resizing.
	* If <= zero, they set the cropping of the '''right''' and '''bottom''' edges respectively, before resizing.		* If <= zero, they set the cropping of the '''right''' and '''bottom''' edges respectively, before resizing.
	Note there are certain ~~restrictions~~:		Note, there are certain limits:
	* ~~{{FuncArg\|src_width}} cannot be >= (~~{{FuncArg\|clip}}.[[Clip_properties\|Width]] - {{FuncArg\|src_left}})		* {{FuncArg\|clip}}.[[Clip_properties\|Width]] must be >= ({{FuncArg\|src_left}} + {{FuncArg\|src_width}})
	* {{FuncArg\|~~src_height~~}} ~~cannot be >= (~~{{FuncArg\|clip}}.[[Clip_properties\|~~Height~~]] - {{FuncArg\|~~src_top}})~~		* {{FuncArg\|clip}}.[[Clip_properties\|Width]] must be >  ({{FuncArg\|src_left}} + '''right''')
	~~<div {{ListItemContinue~~}} >		* {{FuncArg\|clip}}.[[Clip_properties\|Height]] must be >= ({{FuncArg\|src_top}} + {{FuncArg\|src_height}})
	~~...this would "un-crop" the clip, which is not allowed.~~		* {{FuncArg\|clip}}.[[Clip_properties\|Height]] must be >  ({{FuncArg\|src_top}} + '''bottom''')
	~~</div>~~		...otherwise it would enlarge ("un-crop") the clip, or reduce width or height to 0, which is not allowed.
	* '''-'''{{FuncArg\|src_width}} ('''right''') ~~cannot be >= (~~{{FuncArg\|clip}}.[[Clip_properties\|~~Width~~]] - {{FuncArg\|~~src_left~~}})
	* '''-'''{{FuncArg\|src_height}} ~~('''bottom'''~~) ~~cannot be >= (~~{{FuncArg\|clip}}.[[Clip_properties\|Height]] - {{FuncArg\|src_top}})
	~~<div {{ListItemContinue}} >~~
	...~~this~~ would reduce ~~clip~~ width or height to 0, which is not allowed.
	</div>		</div>
	</div>		</div>
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	}}		}}

	'''Spline16Resize''', '''Spline36Resize''' and '''Spline64Resize''' are three [[Wikipedia:Spline_interpolation\|Spline based]] resizers. They are the (cubic) spline based resizers from [~~https~~://sourceforge.net/projects/panotools/ Panorama tools] that fit a spline through the sample points and then derives the filter kernel from the resulting blending polynomials. See [http://forum.doom9.org/showthread.php?t=147117 this thread] for the details.		'''Spline16Resize''', '''Spline36Resize''' and '''Spline64Resize''' are three [[Wikipedia:Spline_interpolation\|Spline based]] resizers. They are the (cubic) spline based resizers from [http://sourceforge.net/projects/panotools/ Panorama tools] that fit a spline through the sample points and then derives the filter kernel from the resulting blending polynomials. See [http://forum.doom9.org/showthread.php?t=147117 this thread] for the details.

	The rationale for '''Spline''' is to be as sharp as possible with less ringing artifacts than [[#LanczosResize\|LanczosResize]] produces. '''Spline16Resize''' uses <tt>sqrt(16)=4</tt> sample points, '''Spline36Resize''' uses 6 sample points, etc ... The more sample points used, the sharper your clip will get. Several resizer comparison pages are given in the [[#External Links\|External Links]] section.		The rationale for '''Spline''' is to be as sharp as possible with less ringing artifacts than [[#LanczosResize\|LanczosResize]] produces. '''Spline16Resize''' uses <tt>sqrt(16)=4</tt> sample points, '''Spline36Resize''' uses 6 sample points, etc ... The more sample points used, the sharper your clip will get. Several resizer comparison pages are given in the [[#External Links\|External Links]] section.
Line 256:		Line 252:
	* [http://jeanbruenn.info/2011/10/30/upscaling-in-avisynth-comparison-of-resizers/ ''Upscaling in Avisynth – Comparison of resizers''] \| [http://web.archive.org/web/20140207171106/http://jeanbruenn.info/2011/10/30/upscaling-in-avisynth-comparison-of-resizers/ archived link]		* [http://jeanbruenn.info/2011/10/30/upscaling-in-avisynth-comparison-of-resizers/ ''Upscaling in Avisynth – Comparison of resizers''] \| [http://web.archive.org/web/20140207171106/http://jeanbruenn.info/2011/10/30/upscaling-in-avisynth-comparison-of-resizers/ archived link]
	* [http://web.archive.org/web/20060827184031/http://www.path.unimelb.edu.au/~dersch/interpolator/interpolator.html ''Testing Interpolator Quality''] (Helmut Dersch, Technical University Furtwangen)		* [http://web.archive.org/web/20060827184031/http://www.path.unimelb.edu.au/~dersch/interpolator/interpolator.html ''Testing Interpolator Quality''] (Helmut Dersch, Technical University Furtwangen)
	* [~~https~~://forum.doom9.org/showthread.php?t=172871 Doom9 discussion of resizers for downsizing]		* [http://forum.doom9.org/showthread.php?t=172871 Doom9 discussion of resizers for downsizing]


	== Changelog ==		== Changelog ==
	. . .		. . .

Raffriff42: correction

2016-02-01T01:03:53Z

correction

← Older revision		Revision as of 03:03, 1 February 2016
Line 29:		Line 29:
	...this would "un-crop" the clip, which is not allowed.		...this would "un-crop" the clip, which is not allowed.
	</div>		</div>
	* '''-'''{{FuncArg\|~~src_right~~}} cannot be >= ({{FuncArg\|clip}}.[[Clip_properties\|Width]] - {{FuncArg\|src_left}})		* '''-'''{{FuncArg\|src_width}} ('''right''') cannot be >= ({{FuncArg\|clip}}.[[Clip_properties\|Width]] - {{FuncArg\|src_left}})
	* '''-'''{{FuncArg\|~~src_bottom~~}} cannot be >= ({{FuncArg\|clip}}.[[Clip_properties\|Height]] - {{FuncArg\|src_top}})		* '''-'''{{FuncArg\|src_height}} ('''bottom''') cannot be >= ({{FuncArg\|clip}}.[[Clip_properties\|Height]] - {{FuncArg\|src_top}})
	<div {{ListItemContinue}} >		<div {{ListItemContinue}} >
	...this would reduce clip width or height to 0, which is not allowed.		...this would reduce clip width or height to 0, which is not allowed.

Raffriff42: tweak

2016-02-01T00:58:57Z

tweak

← Older revision		Revision as of 02:58, 1 February 2016
Line 18:		Line 18:

	{{Par2\|src_width, src_height\|int\|(source width, height)}}		{{Par2\|src_width, src_height\|int\|(source width, height)}}
			:See [[#Cropping \|cropping]] discussion below.
	<div {{ListItemContinue\|2}} >		<div {{ListItemContinue\|2}} >
	~~{\| border="0" style="width:52em"~~		As with [[Crop]], these arguments have different functionality, depending on their value:
	~~\|colspan="4"\| See [[#Cropping \|cropping]] discussion below.~~		* If  > zero, these set the '''width''' and '''height''' of the clip before resizing.
	\|-		* If <= zero, they set the cropping of the '''right''' and '''bottom''' edges respectively, before resizing.
	~~\|colspan="4"\|~~ As with [[Crop]], these arguments have different functionality, depending on their value:		Note there are certain restrictions:
	\|-		* {{FuncArg\|src_width}} cannot be >= ({{FuncArg\|clip}}.[[Clip_properties\|Width]] - {{FuncArg\|src_left}})
	~~\|colspan="4"\| {{BoldColor\|#638C9C\|100\|•}}~~ If  > zero, these set the '''width''' and '''height''' of the clip before resizing.		* {{FuncArg\|src_height}} cannot be >= ({{FuncArg\|clip}}.[[Clip_properties\|Height]] - {{FuncArg\|src_top}})
	\|-		<div {{ListItemContinue}} >
	~~\|colspan="4"\| {{BoldColor\|#638C9C\|100\|•}}~~ If <= zero, they set the cropping of the '''right''' and '''bottom''' edges respectively, before resizing.		...this would "un-crop" the clip, which is not allowed.
	\|-		</div>
	~~\|colspan="4"\|~~ Note there are certain restrictions:		* '''-'''{{FuncArg\|src_right}} cannot be >= ({{FuncArg\|clip}}.[[Clip_properties\|Width]] - {{FuncArg\|src_left}})
	\|-		* '''-'''{{FuncArg\|src_bottom}} cannot be >= ({{FuncArg\|clip}}.[[Clip_properties\|Height]] - {{FuncArg\|src_top}})
	~~\| {{BoldColor\|#638C9C\|100\|•}}~~ {{FuncArg\|src_width}}		<div {{ListItemContinue}} >
	\| cannot be >=~~ ~~		...this would reduce clip width or height to 0, which is not allowed.
	\| ({{FuncArg\|clip}}.[[Clip_properties\|Width]] - {{FuncArg\|src_left}});		</div>
	~~\|  this would "un-crop" the clip, which is not allowed.~~
	\|-
	~~\| {{BoldColor\|#638C9C\|100\|•}}~~ {{FuncArg\|src_height}}
	\| cannot be >=
	\| ({{FuncArg\|clip}}.[[Clip_properties\|Height]] - {{FuncArg\|src_top}});
	~~\|  ~~this would "un-crop" the clip, which is not allowed.
	\|-
	~~\| {{BoldColor\|#638C9C\|100\|•}}~~ '''-'''{{FuncArg\|src_right}}
	\| cannot be >=
	\| ({{FuncArg\|clip}}.[[Clip_properties\|Width]] - {{FuncArg\|src_left}});
	~~\|  this would reduce clip width to 0, which is not allowed.~~
	\|-
	~~\| {{BoldColor\|#638C9C\|100\|•}}~~ '''-'''{{FuncArg\|src_bottom}}
	\| cannot be >=
	\| ({{FuncArg\|clip}}.[[Clip_properties\|Height]] - {{FuncArg\|src_top}});
	~~\|  ~~this would reduce clip height to 0, which is not allowed.
	\|}
	</div>		</div>

← Older revision		Revision as of 03:42, 1 February 2016
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	<div {{ListItemContinue\|2}} >		<div {{ListItemContinue\|2}} >
	You have to set "{{FuncArg\|b}} + 2.0 * {{FuncArg\|c}} = 1~~.0"~~ for the numerically ~~most~~ accurate filter. This gives for {{FuncArg\|b}}=0 the maximum value of 0.5 for {{FuncArg\|c}}, which is the [[Wikipedia:Cubic_Hermite_spline#Catmull.E2.80.93Rom_spline\|Catmull-Rom spline]] and a good suggestion for sharpness.		You have to set [{{FuncArg\|b}} + 2{{FuncArg\|c}} = 1] for the most numerically accurate filter. This gives for {{FuncArg\|b}}=0 the maximum value of 0.5 for {{FuncArg\|c}}, which is the [[Wikipedia:Cubic_Hermite_spline#Catmull.E2.80.93Rom_spline\|Catmull-Rom spline]] and a good suggestion for sharpness.

	As {{FuncArg\|c}} exceeds 0.6, the filter starts to [[Wikipedia:Ringing_artifacts\|"ring"]] or overshoot. You won't get true sharpness – what you'll get is exaggerated edges.		As {{FuncArg\|c}} exceeds 0.6, the filter starts to [[Wikipedia:Ringing_artifacts\|"ring"]] or overshoot. You won't get true sharpness – what you'll get is exaggerated edges.