ImageStatistics node

This documentation is for version 1.0 of ImageStatistics (net.sf.openfx.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
HiDPI / hidpi	Boolean	Off	Should be checked when the display area is High-DPI (a.k.a Retina). Draws OpenGL overlays twice larger.
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 (rec709): Use Rec. 709 (0.2126r + 0.7152g + 0.0722b). Rec. 2020 (rec2020): Use Rec. 2020 (0.2627r + 0.6780g + 0.0593b). ACES AP0 (acesap0): Use ACES AP0 (0.3439664498r + 0.7281660966g + -0.0721325464b). ACES AP1 (acesap1): Use ACES AP1 (0.2722287168r + 0.6740817658g + 0.0536895174b). CCIR 601 (ccir601): Use CCIR 601 (0.2989r + 0.5866g + 0.1145b). Average (average): Use average of r, g, b. Max (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.