Category
Function
Applies histogram equalization to a field.
Syntax
equalized = Equalize(data, bins, min, max, ihist, ohist);
Inputs
Name  Type  Default  Description 

data  scalar field  none  data to be equalized 
bins  integer  input dependent  number of equalization bins 
min  scalar or field  min of data  lower bound of equalization 
max  scalar or field  max of data  upper bound of equalization 
ihist  field  histogram of data  input distribution 
ohist  field  uniform distribution  output distribution 
Outputs
Name  Type  Description 

equalized  scalar field  histogramequalized data 
Functional Details
This module equalizes an input data field so that the histogram of the output approximates a specified distribution (ohist), which by default is a uniform distribution.
If data specifies a series, the histogram of the entire series is used to construct the probability distribution, which is then applied to each field in the series.
data  is the scalar data field to be equalized. 
bins  is the number of bins to be used in creating the equalization histogram. The default value is 100, unless data consists of byte values. In that case, the default is: max  min + 1 
min and max  specify the range of the data values to be equalized. Values outside that range remain unchanged. Notes:

ihist  is the histogram used to determine the equalization function required, and by default it is the histogram of data. If ihist is specified explicitly and the number of bins specified does not match the number in the histogram, the module resamples the histogram so that it contains the specified number. 
ohist  is the type of output histogram desired. By default, the module equalizes to a uniform distribution. You can equalize to some other distribution by specifying an appropriate histogram for this parameter. 
Note: A wellformed histogram (for ihist and ohist) consists of a field with a "positions" component that defines the bins of the histogram; a "connections" component that connects the positions; and a "data" component that contains the number of items in each bin. The data should be connection dependent ("dep" "connections").
Components
Equalize modifies the data component. All other components are unmodified.
Example Visual Programs
UsingEqualize.net
See Also
[ OpenDX Home at IBM  OpenDX.org ]