Color adjustments


These sliders implement the color correction to enhance your video without sacrificing of the processing speed.
That's because the parameters are embedded into the matrix for YUV->RGB transformation, so it does not matter for the speed whether you ask for color correction or not.

A view of just one tab of the dialog

Brightness.

This is adjusted by shifting the values of all three (intensity and two color) channels equally after the contrast settings were applied.
Setting +50 means shifting the middle level (127) to the maximum (255).
Setting -50 means shifting the middle level (127) to the minimum (0).

Contrast.

This slider stretches (or shrinks) the ranges of all three channels equally.
Setting +50 will double the range of values, and
setting -50 will halve it.

Saturation.

This stretches (or shrinks) the ranges of the two color channels equally.

Saturation Balance.

This stretches the range of one color channel while proportionally shrinking the range of another.
With this feature, you can correct the effects of distorted colors in your video source, such as "yellowish film" or "pink faces".

Shift Red,  Shift Blue.

These sliders adjust the color tint by shifting the values of the corresponding color channel.
The color map represents the color tint that you can obtain by combining the two sliders.
For example, to reduce the yellow tint in the source video, you need to shift from the Yellow area to the Neutral (at the center). That is, you have to set Shift Red to negative and Shift Blue to positive.

Note, that unlike the Saturation Balance these sliders will shift the whole range of color values, so make sure that the dark areas in your video remain colored properly.

Percentage of saturated pixels.

This information helps finding the optimal color correction settings.
The numbers in frames are the relative amount of pixels that get their levels (Intensity, Color-U, or Color-V) exceeded the range of 0...255 due to the color correction (the parameters listed above).
The exceeding values were clipped in order to fit into that range (8 bit per color channel, i.e. 24-bit or True Color).

It is recommended at first to locate a frame in Preview window with most vivid colors and then adjust Brightness and Contrast so that the Intensity percentage becomes about 0.1% for both high and low levels.

The percentage for the color channels can be a little bit higher, which is controlled by the two Saturation sliders and the two Color shift sliders.

Preview.

This button will open an additional window where you can watch the effect of your color adjustments.
The time lag is present only when changing frames, but once the frame is selected, the effect of changing the color parameters is displayed right away.

The Preview button is disabled if no video file was opened in VirtualDub.

Bypass.

This checkbox allows turning off the color correction in order to compare the corrected and the original images.
If checked this will bypass all current setting for color correction.
Can be used only with Preview.


Smoothing Spot detection Intensity locking

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Updated: 01/22/2009