 |
 |
 |
PlotScanline |
Function
The PlotScanline function is an analysis tool that examines a line of an image and graphs the intensity of each channel per X position. It greatly helps to determine what a color correction function is doing. Although it can be attached to any image for analysis, it is often attached to a horizontal Ramp to observe the behavior of a color correction. Switch the Viewer to view the alpha channel (press A in the Viewer), and see the behavior of the alpha channel.
The following are some examples of using the PlotScanline function.
Example 1
A 256x256 8-bit black and white Ramp. Since we have a smooth gradation, with the center at .5, we see a straight line. Moving the center to .75 pushes the center to the right, making the entire image darker. This is reflected in the PlotScanline:
|
|
|
|
Example 2
In this example, some color correction nodes are inserted and the values are adjusted. The PlotScanline indicates exactly what data gets clipped, crunched, compressed, or confused.
 |
 |
|
Parameters
|
Type
|
Defaults
|
Function
|
| width,height |
int
|
width, 512
|
The width and height of the PlotScanline. You probably want to set the width to 256 on an 8-bit image to get 1-to-1 correspondence. |
| line |
int
|
0
|
The Y-line of the image to be analyzed. On a horizontal ramp, this doesn't matter, since they are all identical. |
Synopsis
image PlotScanline( image, int width, int height, int line );
Script
image = PlotScanline(image, width, height, line);
Command Line
shake -plotscanline width height line
See Also
Histogram