# KernelDeint

## Abstract

author: Donald A. Graft
version: 1.4.0
download: http://neuron2.net/mine.html
category: Deinterlacing & Pulldown Removal
requirements: YV12 & YUY2 & RGB Colorspace
license: GPL

### Introduction

This filter deinterlaces using a kernel approach. It gives greatly improved vertical resolution in deinterlaced areas compared to simple field discarding.

If you set the threshold to 0, you can get totally artifact free results (due to lack of thresholding) but with much less loss of vertical resolution than simple field discarding. For optimal results, however, set a motion threshold that allows static areas of the picture to be passed through. In this mode, the kernel-based deinterlacing of the moving areas preserves their vertical resolution compared to simple interpolation.

The filter accepts RGB, YUY2, or YV12 input.

To use this filter as a post-processor for Telecide(), use the following script:

    Telecide(..., post=1, hints=true)
    KernelDeint(...)

### Function Syntax

KernelDeint() takes the following named parameters:

order (0-1, default none!) This parameter defines the field order of the clip. It is very important to set this correctly. Use order=0 for bottom field first (bff). Use order=1 for top field first (tff). You must specify order; DGBob throws an exception if you omit this parameter.

It is essential to set the field order properly for correct rendering. Because setting it correctly is so important, you are strongly encouraged not to make assumptions about the field order of a clip, but rather to verify the field order using the following procedure.

To determine the field order, make an Avisynth script that serves the raw clip without any processing. If it were an AVI, then just AviSource() would be used. For our examples, we'll use AviSource(). Add a script line to separate the fields using top field first, as follows:

    AviSource("your_clip.avi")
    AssumeTFF().SeparateFields()

Now serve the script into VirtualDub and find an area with motion. Single step forward through the motion. Note whether the motion progresses always forward as it should, or whether it jumps back and forth as it proceeds. For example, if the field order is wrong, an object moving steadily from left to right would move right, then jump back left a little, then move right again, etc. If the field order is correct, it moves steadily to the right.

If the motion is correct with AssumeTFF().SeparateFields(), then your field order is top field first and you must set order=1. If the motion is incorrect, then your field order is bottom field first and you must set order=0. If you are want to double check things, you can use AssumeBFF.SeparateFields() to check correct operation for bottom field first.

threshold (0-255, default 10) This parameter defines the "motion" thresold. Moving areas are kernel-deinterlaced while non-moving areas are passed through. Use the map parameter to tweak the threshold parameter so that just the combed areas of the frame are deinterlaced.

sharp (true/false, default false) This parameter, when set to true, selects a kernel that provides better vertical resolution and performs some sharpening of the video. For less sharpening but also less vertical resolution, set this parameter to false.

twoway (true/false, default false) This parameter, when set to true, selects a kernel that includes both the previous and the following fields for deinterlacing. When set to false, the kernel includes only the previous field. The latter one-way kernel is faster, crisper, and gives less blending (this last advantage makes the filter perform better on anime). The twoway parameter is included in case users want to achieve the behavior of previous versions.

map (true/false, default false) This parameter, when set to true, shows the areas that are "moving" as determined by the threshold parameter and which will be kernel-deinterlaced. Use this parameter to assist in tweaking the threshold parameter.

debug (true/false, default false) This parameter, when set to true, enables debug ouput via the DebugView utility. Currently, it shows the version number of the filter and, if hints are present from Telecide(), whether frame are hinted as progressive or interlaced. If hints are not present, the debug output shows all frames as interlaced.

Copyright © 2003, Donald A. Graft, All Rights Reserved.

For updates and other filters/tools, visit my web site:
http://neuron2.net/

`$Date: 2005/10/01 23:09:51 $`