PixelAnalyzer

Function
The PixelAnalyzer node, located in the Other tab, allows you to examine one or more areas of pixels over a frame range. The data is then stored as the average, minimum, and maximum values of each area on a frame-by-frame basis. This information can be used to assist in matching colors, or to reduce flicker in a plate, that are typically fed into expressions in a Color node.

The working method for analyzing color is similar to the Tracker. However, the analyzer does not do any tracking itself. It merely grabs color values.

Analyzing An Area

  1. Attach the PixelAnalyzer node to an image.
  2. Place the box in an area you wish to examine and adjust the box size as necessary.
  3. The box may be manually animated by using the Viewer Autokey button. Otherwise, it will remain stationary.
  4. You may wish to create several analysis areas by using the Add button at the bottom of the Parameters list.
  5. Verify the frame range you wish to examine in the analysisRange parameter.
  6. Press the Analyze Forward (or Backward button) in the Viewer.
    The analysis begins from the current frame. Each active box (controlled by the visibility toggle by the areaName) grabs color values for its area and then calculates the average, minimum, and maximum values for that area.

To delete an area box, do one of the following:

  1. In the Viewer, select the box (click the box), and then click Delete in the
    PixelAnalyzer parameters.
  2. In the PixelAnalyzer parameters, click the areaName text field (highlighted green) and click Delete.

To save the data of an area:

  1. Click the Save button in the lower portion of the PixelAnalyzer parameters.
    The “Save pixel analysis data to file” window appears.
  2. Select or create the directory to store the saved the data, name the file, and click OK.
Parameters
Type
Defaults
Function
analysisRange
int
 1 The frames over which the analysis is done. Analysis always starts on the current frame.
limitProcessing
int
 1 (on) When the analysis is launched, this toggle indicates if only the area inside the area boxes should be updated.
areaName
string
 area1,2, etc The name of each area box. The user may change this name. Doing so causes the parameters to change their names.
areaAverageRed, Green, Blue, Alpha
float
 0 The average of all of the pixels in the area.
areaMinimumRed, Green, Blue, Alpha float 0 The minimum value of every pixel in the area.
areaMaximumRed, Green, Blue, Alpha float 0 The maximum value of every pixel in the area.
areaX, Y int width/2, height/2 The search area center.
areaWidth, Height int 30 The search area width and height.
areaVisible int 1 A toggle to indicate if the area box is visible, and therefore gets updated when the Analyze button is pressed. This is not typically controlled by the user, but is a result of the visibility toggle next to the area name parameter.
areaEnabled int 10  


Synopsis

image PixelAnalyzer( 
  image In, 
  const char * anaylsisRange,
  int limitProcessing, 
  const char * area1Name,
  float <area1Name>AverageRed, 
  float <area1Name>AverageGreen, 
  float <area1Name>AverageBlue,
  float <area1Name>AverageAlpha, 
  float <area1Name>MinRed, 
  float <area1Name>MinGreen,
  float <area1Name>MinBlue, 
  float <area1Name>MinAlpha, 
  float <area1Name>MaxRed,
  float <area1Name>MaxGreen,
  float <area1Name>MaxBlue, 
  float <area1Name>MaxAlpha,
  int <area1Name>X, 
  int <area1Name>Y, 
  int <area1Name>Width, 
  int <area1Name>Height, 
  int <area1Name>Visible, 
  int <area1Name>Enabled, 
  ...area2 parameters...
);


Script

image PixelAnalyzer( 
  In, 
  anaylsisRange,
  limitProcessing, 
  “area1Name”,
  <area1Name>AverageRed, 
  <area1Name>AverageGreen, 
  <area1Name>AverageBlue,
  <area1Name>AverageAlpha, 
  <area1Name>MinRed, 
  <area1Name>MinGreen,
  <area1Name>MinBlue, 
  <area1Name>MinAlpha, 
  <area1Name>MaxRed,
  <area1Name>MaxGreen,
  <area1Name>MaxBlue, 
  <area1Name>MaxAlpha,
  <area1Name>X, 
  <area1Name>Y, 
  <area1Name>Width, 
  <area1Name>Height, 
  <area1Name>Visible, 
  <area1Name>Enabled, 
  ...area2 parameters..,
  );


Command Line

Not appropriate for command line use.