Class Histogram1DCreator

java.lang.Object
net.sourceforge.jiu.ops.Operation
net.sourceforge.jiu.color.analysis.Histogram1DCreator

public class Histogram1DCreator extends Operation
This class creates one-dimensional histograms for images with integer samples. Only IntegerImage objects are supported.

Existing histogram objects can be given to this operation to be reused. Give an existing Histogram1D object to this operation via setHistogram(Histogram1D).

The histogram can be created for any channel of an IntegerImage. The first channel (index 0) is the default channel. Use setImage(IntegerImage, int) to specify another one.

Note: Before JIU 0.10.0 there was a single HistogramCreator class.

Usage example

Creates a histogram for the third channel of an image, whose index is two because channels are zero-based:
 Histogram1DCreator hc = new Histogram1DCreator();
 hc.setImage(image, 2);
 hc.process();
 Histogram1D hist = hc.getHistogram();
 
If you just want to learn the number of different samples in an image, there's a static convenience method count for that. Again, we use the third channel:
Integer numUsedSamples = Histogram1DCreator.count(image, 2);
Since:
0.10.0
Author:
Marco Schmidt
  • Field Details

  • Constructor Details

    • Histogram1DCreator

      public Histogram1DCreator()
  • Method Details

    • count

      public static Integer count(IntegerImage image)
      Static convenience method to count the number of different samples in the first channel of the argument image.
      Parameters:
      image - the IntegerImage to be examined
      Returns:
      the number of different values or null on failure (image is null, histogram data structure could not be allocated)
      Since:
      0.15.0
    • count

      public static Integer count(IntegerImage image, int channelIndex)
      Static convenience method to count the number of different samples in one of the channels of the argument image.
      Parameters:
      image - the IntegerImage to be examined
      channelIndex - the zero-based index of the channel to use
      Returns:
      the number of different values or null on failure (image is null, channel index is invalid, histogram data structure could not be allocated)
      Since:
      0.15.0
    • createHistogramIfNecessary

      private void createHistogramIfNecessary()
    • getHistogram

      public Histogram1D getHistogram()
      Returns the histogram used in this operation.
      Returns:
      histogram object, newly-created or reused one
      See Also:
    • process

      public void process() throws MissingParameterException, WrongParameterException
      Description copied from class: Operation
      This method does the actual work of the operation. It must be called after all parameters have been given to the operation object.
      Overrides:
      process in class Operation
      Throws:
      MissingParameterException - if any mandatory parameter was not given to the operation
      WrongParameterException - if at least one of the input parameters was not initialized appropriately (values out of the valid interval, etc.)
    • setHistogram

      public void setHistogram(Histogram1D histogram)
      Sets a histogram object to be used for this operation. Within process() it will be checked if this histogram is large enough for the image.
      See Also:
    • setImage

      public void setImage(IntegerImage newImage)
      Set the image for which the histogram is to be initialized. The first channel (index 0) is used by default.
      Parameters:
      newImage - image object to be used
      See Also:
    • setImage

      public void setImage(IntegerImage newImage, int imageChannelIndex)
      Set the image and the channel index for which the histogram is to be initialized.
      Parameters:
      newImage - image object to be used
      imageChannelIndex - must not be negative and must be smaller than newImage.getNumChannels()
      See Also: