Field Blending

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Introduction

Field blending, also known as "ghosting" is a deinterlacing method that is unacceptable at SDA. It's too easy to get stuck with a cheap capture card and cheap software that will produce a video with this effect. I think there may also be some fault with the user. People new to video capturing/editing will think they've done something wrong when they see "all those weird lines" in an interlaced frame and choose a different and incorrect interlacing setting, most likely progressive field blending.


The field blending process

1. A single interlaced frame. It has two distinct fields, which I will call field A and field B, happening a split second apart.
Fieldblending ABi.png
2. The fields have been split. Field A has the even-numbered lines, while field B has the odd-numbered lines.

Fieldblending A1.png Fieldblending B1.png
3. The actual vertical height of field A and B. Nothing necessarily bad has happened yet...

Fieldblending A2.png Fieldblending B2.png
4. Problem number one! The fields are resized to the original height. Vertical detail is lost.

Fieldblending A3.png Fieldblending B3.png
5. The final stage. Field A and B are blended together at different opacities. The result is a "ghosting" effect.

Fieldblending ABfb.png


More examples

Fieldblending Zelda.jpg

Fieldblending mario.PNG

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