ImageStatistics node¶
This documentation is for version 1.0 of ImageStatistics.
Description¶
Compute image statistics over the whole image or over a rectangle. The statistics can be computed either on RGBA components, in the HSVL colorspace (which is the HSV colorspace with an additional L component from HSL), or the position and value of the pixels with the maximum and minimum luminance values can be computed.
The color values of the minimum and maximum luma pixels for an image sequence can be used as black and white point in a Grade node to remove flicker from the same sequence.
Inputs¶
Input  Description  Optional 

Source  No 
Controls¶
Parameter / script name  Type  Default  Function 

Restrict to Rectangle / restrictToRectangle 
Boolean  On  Restrict statistics computation to a rectangle. 
Bottom Left / bottomLeft 
Double  x: 0 y: 0  Coordinates of the bottom left corner of the rectangle 
Size / size 
Double  w: 1 h: 1  Width and height of the rectangle 
Auto Update / autoUpdate 
Boolean  On  Automatically update values when input or rectangle changes if an analysis was performed at current frame. If not checked, values are only updated if the plugin parameters change. 
Interactive Update / interactive 
Boolean  Off  If checked, update the parameter values during interaction with the image viewer, else update the values when pen is released. 
Min. / statMin 
Color  r: 0 g: 0 b: 0 a: 0  Minimum value. 
Max. / statMax 
Color  r: 0 g: 0 b: 0 a: 0  Maximum value. 
Mean / statMean 
Color  r: 0 g: 0 b: 0 a: 0  The mean is the average. Add up the values, and divide by the number of values. 
S.Dev. / statSDev 
Color  r: 0 g: 0 b: 0 a: 0  The standard deviation (S.Dev.) quantifies variability or scatter, and it is expressed in the same units as your data. 
Skewness / statSkewness 
Color  r: 0 g: 0 b: 0 a: 0  Skewness quantifies how symmetrical the distribution is.
• A symmetrical distribution has a skewness of zero.
• An asymmetrical distribution with a long tail to the right (higher values) has a positive skew.
• An asymmetrical distribution with a long tail to the left (lower values) has a negative skew.
• The skewness is unitless.
• Any threshold or rule of thumb is arbitrary, but here is one: If the skewness is greater than 1.0 (or less than 1.0), the skewness is substantial and the distribution is far from symmetrical.

Kurtosis / statKurtosis 
Color  r: 0 g: 0 b: 0 a: 0  Kurtosis quantifies whether the shape of the data distribution matches the Gaussian distribution.
•A Gaussian distribution has a kurtosis of 0.
•A flatter distribution has a negative kurtosis,
•A distribution more peaked than a Gaussian distribution has a positive kurtosis.
•Kurtosis has no units.
•The value that this plugin reports is sometimes called the excess kurtosis since the expected kurtosis for a Gaussian distribution is 0.0.
•An alternative definition of kurtosis is computed by adding 3 to the value reported by this plugin. With this definition, a Gaussian distribution is expected to have a kurtosis of 3.0.

Analyze Frame / analyzeFrame 
Button  Analyze current frame and set values.  
Analyze Sequence / analyzeSequence 
Button  Analyze all frames from the sequence and set values.  
Clear Frame / clearFrame 
Button  Clear analysis for current frame.  
Clear Sequence / clearSequence 
Button  Clear analysis for all frames from the sequence.  
HSVL Min. / statHSVLMin 
Color  h: 0 s: 0 v: 0 l: 0  Minimum value. 
HSVL Max. / statHSVLMax 
Color  h: 0 s: 0 v: 0 l: 0  Maximum value. 
HSVL Mean / statHSVLMean 
Color  h: 0 s: 0 v: 0 l: 0  The mean is the average. Add up the values, and divide by the number of values. 
HSVL S.Dev. / statHSVLSDev 
Color  h: 0 s: 0 v: 0 l: 0  The standard deviation (S.Dev.) quantifies variability or scatter, and it is expressed in the same units as your data. 
HSVL Skewness / statHSVLSkewness 
Color  h: 0 s: 0 v: 0 l: 0  Skewness quantifies how symmetrical the distribution is.
• A symmetrical distribution has a skewness of zero.
• An asymmetrical distribution with a long tail to the right (higher values) has a positive skew.
• An asymmetrical distribution with a long tail to the left (lower values) has a negative skew.
• The skewness is unitless.
• Any threshold or rule of thumb is arbitrary, but here is one: If the skewness is greater than 1.0 (or less than 1.0), the skewness is substantial and the distribution is far from symmetrical.

HSVL Kurtosis / statHSVLKurtosis 
Color  h: 0 s: 0 v: 0 l: 0  Kurtosis quantifies whether the shape of the data distribution matches the Gaussian distribution.
•A Gaussian distribution has a kurtosis of 0.
•A flatter distribution has a negative kurtosis,
•A distribution more peaked than a Gaussian distribution has a positive kurtosis.
•Kurtosis has no units.
•The value that this plugin reports is sometimes called the excess kurtosis since the expected kurtosis for a Gaussian distribution is 0.0.
•An alternative definition of kurtosis is computed by adding 3 to the value reported by this plugin. With this definition, a Gaussian distribution is expected to have a kurtosis of 3.0.

Analyze Frame / analyzeFrameHSVL 
Button  Analyze current frame as HSVL and set values.  
Analyze Sequence / analyzeSequenceHSVL 
Button  Analyze all frames from the sequence as HSVL and set values.  
Clear Frame / clearFrameHSVL 
Button  Clear HSVL analysis for current frame.  
Clear Sequence / clearSequenceHSVL 
Button  Clear HSVL analysis for all frames from the sequence.  
Luminance Math / luminanceMath 
Choice  Rec. 709  Formula used to compute luminance from RGB values.
Rec. 709: Use Rec. 709 (0.2126r + 0.7152g + 0.0722b).
Rec. 2020: Use Rec. 2020 (0.2627r + 0.6780g + 0.0593b).
ACES AP0: Use ACES AP0 (0.3439664498r + 0.7281660966g + 0.0721325464b).
ACES AP1: Use ACES AP1 (0.2722287168r + 0.6740817658g + 0.0536895174b).
CCIR 601: Use CCIR 601 (0.2989r + 0.5866g + 0.1145b).
Average: Use average of r, g, b.
Max: Use max or r, g, b.

Max Luma Pixel / maxLumaPix 
Double  x: 0 y: 0  Position of the pixel with the maximum luma value. 
Max Luma Pixel Value / maxLumaPixVal 
Color  r: 0 g: 0 b: 0 a: 0  RGB value for the pixel with the maximum luma value. 
Min Luma Pixel / minLumaPix 
Double  x: 0 y: 0  Position of the pixel with the minimum luma value. 
Min Luma Pixel Value / minLumaPixVal 
Color  r: 0 g: 0 b: 0 a: 0  RGB value for the pixel with the minimum luma value. 
Analyze Frame / analyzeFrameLuma 
Button  Analyze current frame and set min/max luma values.  
Analyze Sequence / analyzeSequenceLuma 
Button  Analyze all frames from the sequence aand set min/max luma values.  
Clear Frame / clearFrameLuma 
Button  Clear luma analysis for current frame.  
Clear Sequence / clearSequenceLuma 
Button  Clear luma analysis for all frames from the sequence. 