GENERAL

The Curves interface allows you to re-map the luminance, hue,saturation or individual color curves of a shot by manipulating a curve that represents input and output ranges.



In total there are fourteen curves that can be manipulated and which can be selected using the buttons on the left of the curve display:

• Overall luminance (Master) and red, green and blue channel luminance,
• Alpha, Hue, Saturation and Luminance,
• Hue versus Saturation, Hue versus Luminance
• Saturation versus Hue, Saturation versus Luminance,
• Luminance versus Hue and Luminance versus Saturation

Each curve has a number of control points that can be adjusted within the curve display. There are also Bezier handles on each point that allow you to adjust the shape of the curve through the three control points. The sensitivity of the control points is relatively moderate;you can hold down the Quick key: shift to modify the sensitivity of the control points in order to reshape the curve.

In the background of each of the curve displays, the full histogram of the current shot in the Player is drawn. Rescaling the Histogram on the Statistics panel as explained in Chapter 5 - The Player, will also rescale it in the background of the curve display.

The horizontal axis of the curve display represents the source image range from low to high. The vertical axis represents the resulting range. New values are calculated by projecting up from the horizontal axis at a particular value; and then the intersection point with the curve is projected left to the resulting value. The curve display is, in essence, a visual representation of a Look Up Table that allows you to easily make interactive adjustments.

CURVE TOOLS

CURVE EDITOR

The Curve Editor button opens the Animate Curve Editor where the parameters can be adjusted over time and the number of control points can be changed. The Curve Editor is discussed in more detail later in this chapter.

MATCH GRADE

The Match Grade controls allow you to manipulate the RGB channel curves by selecting colors rather than manipulating the curves directly. Using the corresponding color selectors you can pick your Source color and Target color. Next, use the Add Match button to adjust the RGB curves when the source color is remapped to the target color.

BY-PASS

When enabled - SCRATCH ignores all the curve settings.

RESET

Reset only the current selected curve.