Class 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
    • Constructor Detail

      • Histogram1DCreator

        public Histogram1DCreator()
    • Method Detail

      • 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()
      • 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:
        getHistogram()
      • 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(IntegerImage, int)
      • 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:
        setImage(IntegerImage)