Blur / Sharpen

Blur a simple 3x3 kernel blurring filter.
Sharpen is 3×3 kernel sharpening filter; the inverse of Blur.

Syntax and Parameters

Blur (clip, float amount)
Blur (clip, float amountH, float amountV, bool "mmx")
Sharpen (clip, float amount)
Sharpen (clip, float amountH, float amountV, bool "mmx")
clip

Input clip; all color formats supported.

amount

Blurring or sharpening strength:

  • Blur: the allowable range is from -1.0 to +1.58

  • Sharpen: the allowable range is from -1.58 to +1.0

  • Negative Blur actually sharpens the image; in fact Sharpen(n) is just an alias for Blur(-n).

amountH, amountV

You can use 2 arguments to set independent vertical and horizontal blurring or sharpening, for example:

  • Blur(0,1) will blur vertical only, perhaps to blend interlaced lines together.

  • Blur(1,0) will blur horizontal only.

  • If amountV is not specified, it defaults to amountH.

mmx

Deprecated - this parameter is simply ignored.

Notes

If you need a larger radius Gaussian blur, try chaining several Blurs together:

Blur(1.0).Blur(1.0).Blur(1.0)

Chaining calls to Sharpen is not a good idea, as the image quickly deteriorates.

Developer notes

Blur uses the kernel [(1−1/2^amount)/2, 1/2^amount, (1−1/2^amount)/2]. The largest allowable argument for Blur is log2(3) (which is about 1.58), which corresponds to a (1/3,1/3,1/3) kernel. A value of 1.0 gets you a (1/4,1/2,1/4) kernel for example. Likewise Blur(1.0).Blur(1.0) is a convolution of the kernel (1/4,1/2,1/4) with itself, being a (1/4,1/2,1/4)*(1/4,1/2,1/4) = (1/16,4/16,6/16,4/16,1/16) kernel. It can be read of Pascal's triangle.

Changelog

Version

Changes

AviSynth+ 3.7.0

Fix: Blur right side garbage: 16 bit+AVX2+non mod32 width

AviSynth+ r2664

Fix: YUY2 Sharpen overflow artifacts - e.g. Sharpen(0.6)

AviSynth+ r2636

Fix: Blur/Sharpen crashed when YUY2.width<8, RGB32.width<4, RGB64.width<2

AviSynth+ r2632

Enhanced: Blur, Sharpen - AVX2 for 8-16 bit planar formats and SSE2 for 32 bit float formats.

AviSynth+ r2487
Blur/Sharpen: support for all planar RGB(A)/YUV(A) and RGB32/64 formats.
Enhanced: Blur, Sharpen- SSE2/SSE4 FOR 10-16 bits planar and RGB64.
Fix: Blur width=16 (YV12 width=32)

AviSynth+ r2290

Blur/Sharpen: added 16/32 bit support.

AviSynth+ r1576
Blur/Sharpen: mmx parameter ignored.
Blur/Sharpen: filters now have C and SSE2 versions.

AviSynth 2.6.0

Blur/Sharpen: added support for Y8, YV411, YV16 and YV24 color formats.

AviSynth 2.5.8

MMX routines fixed (have full 8 bit precision now); mmx=true by default.

AviSynth 2.5.7

Added mmx option.

$Date: 2022/02/28 11:37:04 $