Motion Compensated Denoise plugin

Motion Compensated Denoise plugin is the combination of per-channel temporal denoise, previously used in plugin BPP_AdvDenoise, and the "motion detector", that allows to minimize the disturbances introduced by temporal denoise.

In contrast to spatial denoise, where noise is estimated as deviation the values of pixels from their nearest neighbours in one frame, temporal denoise process pixels in series of frames (in time). Due to this on a static pictures temporal denoise ensures saving picture details and sharpness of object borders. Nevertheless, in dynamic scenes every "useful" change in the picture with the level below the set threshold of noise are inevitably treated as noise that should be cancelled, that results in texture blurring, eppearing of trails and contours behind the moving objects. Analysis of changes in scene allows for temporal denoise to consider every motion in scene and to make correct decision concerning the complicated parts of picture.

On a screenshots below it is shown a work of BPP_MCDenoise plugin with motion compensation turned on (top half of picture) and off (bottom half of picture). The noise threshold is intentionally risen up to 100.

An additional bonus from using motion compensation is the possibility to calculate the signal/noise ratio (SNR) over the whole picture, that allows to automatically support optimal level of noise threshold in plugin. Nevertheless, in complicated dynamic scenes, that partially may be percepted as noise, the noise threshold will grow automatically. This may lead to appearing of artifacts seen as blocks as in MPEG compression. Due to this an automatic adjust (Auto) should be turned off after an optimal level of noise threshold will be achieved.

If motion compensation is turned off, the work of plugin is similar to the work of BPP_AdvDenoise plugin mentioned above. In this case the calculation of signal/noise ratio and automatic adjust will be unavailable.

Plugin works with picture in YUV format, where there are three components – luminosity (Y) and two chromatic components (UV). Luminosity component of picture brings the most of information about picture and every noise and distortions in Y channel is most visible. It is highly recommended not to rise the noise threshold on Y channel higher than the value that is set automatically. This won't make picture more clear but will add visible artifacts.

Two chromatic components are responsible for coloring the picture and the disturbances in U/V channels are not so visible. On relatively small values of noise threshold you may turn off motion compensation for that channels, reducing the CPU load with that.

For Y channel the noise threshold on which you may turn off the motion compensation is about 10…15 points, for U/V channels – 30…40 points.

Demo mode, that may be activated during plugin setup, allows to estimate the result of plugin work. With that the screen is divided on two parts, where the top half is processed by the plugin, while the bottom half is untouched.

List of changes

• First release.

• Added settings saving under Windows 7.

• Added support of Behold TV instances.

Link to the plugin: BPP_MCDenoise_v102.zip (46.8 kb)

01.03.11