VapourSynth-Destripe

A descale wrapper for anime destriping.

Prerequisites

• VapourSynth version R46 or newer
• vapoursynth-descale
• VapourSynth R49 and Descale R3 or newer for Spline64 support. A recent version since this commit for using cropping parameters src_width and src_height.
• An optional filter fixing borders before descaling. It should work for GRAY16 input with top and bottom options. It is called only if nontrivial border widths are provided. The default is EdgeFixer.

How it works

Some striped (aka cross-conversion, or 縞縞) anime artifacts are caused by improper upscaling by field. Destripe manually descales by field.

Usage

The first plane of the input clip will be internally converted to GRAY16 if fixing borders is requested, then GRAYS, and be processed. The output has the same format as the first plane of the input.

from destripe import Destripe

down = Destripe(clip clip[, int width=1280, int height=360, str kernel='bicubic', float b=0, float c=1/2, int taps=3, float[] src_left=[0, 0], float[] src_top=[0, 0], float[] src_width=[width, width], float[] src_height=[height, height], func fix_border_func=vs.core.edgefixer.Continuity, int[] fix_top=[0, 0], int[] fix_bottom=[0, 0], bool showdiff=False])

down, diff = Destripe(clip, ..., showdiff=True)

Parameters:

• width, height
  The destination descaled size for each field. For example, if you believe the native resolution was 1280x720, then each field should be 1280x360.
• kernel, b, c, taps
  Parameters of the resizers. See Descale's page.
• src_left, src_top, src_width, src_height
  Specify the cropping parameters for the top field and the bottom field, respectively. They refer to the initial upscale, see this link. Usually you need to modify src_top until satisfactory. Note that Descale only accepts positive values of src_width and src_height, so negative or zero inputs will be replaced by values of width and height, respectively.
• fix_border_func, fix_top, fix_bottom
  If specified, a border fixing filter will be applied to the top and bottom borders for each field, respectively, before descaling.
• showdiff
  Set to True to include the de-rescale absolute error diff in the return list. diff has the same format as the first plane of clip.

Notes:

• IVTC should be taken prior to destriping, since this script doesn't deal with field order.
• Bad borders could be amplified while descaling. Tweaking fix_top and fix_bottom may and may not be better than fixing edges before calling Destripe.
• Resizer settings could cause a position shift of the output from the source and you are supposed to fix by yourself.

Examples

In these examples clip already has its borders fixed before processing.

Example 1

down = Destripe(clip, 1280, 360, kernel='spline64', src_top=[1/6, 1/6])
up = core.resize.Spline64(down, 1920, 1080, src_top=1/3)

See the comparison.

Example 2

down = Destripe(clip, 1280, 360, kernel='bicubic', b=0, c=1/3, src_top=[1/12, -1/12])
up = core.resize.Bicubic(down, 1920, 1080, filter_param_a=0, filter_param_b=1/3)

See the comparison.

Related

• 縞縞対策 from anibin's blog
• CullResize, anibin's AVS Destripe
• CullResize, DJATOM's 64-bit port

Thanks

joletb, NiTr0gLiTcH, xyx98

License

MIT.