Grain-Degrain Project

• Project: Dr. Dmitriy Vatolin
• Implementation, ideas: Konstantin Strelnikov, Maxim Makhinya

We developed new methods of removing and applying of the film grain (specific type of noise that is usually present in materials that were captured from film). Our methods allow extraction of film grain information from video and using it for applying of the grain that is very similar to original.
Some examples and explanation you can find below.

Results

Here are three examples of film grain from real video, it could be easily seen that film grain has another structure than digital noise. In most cases film grain makes video more natural and also masks some small artifacts:

Scaled part of frame from DA

Scaled part of frame from MI

Scaled part of frame from DTs

We have developed several methods for film grain removal including temporal and spatial noise filtration; you can find few examples below:

We are proposing two types of grain parameters estimation:

• Noise parameters estimation
• Finding the best matching pattern in the predefined database

And three types of grain generation:

• Using estimated noise parameters
• Using patches from database
• Using analytical approximation of grain structure

An example of visual comparison for grain generation you can find below:

We have obtained these results by original video de-graining, determining grain parameters and applying grain to the de-grained video. Structures of grain in the regrained frames look very similar to the original sources.

The following example shows how regraining technique helps to increase quality and makes compression artifacts significantly less noticeable:

Source fragment from DA

Regraining results

These methods provides possibility to add grain to any other video, making it more natural (for example adding grain to synthetic video). This also makes compressed video look better especially in case when original grain was corrupted by lossy video encoder.

Download

Please contact us if you are interested in a commercial license.

E-mail: video@graphics.cs.msu.ru