Class PopularityQuantizer

All Implemented Interfaces:
RGBQuantizer, RGBIndex

public class PopularityQuantizer extends ImageToImageOperation implements RGBIndex, RGBQuantizer
Performs the popularity color quantization algorithm that maps an image to the colors occurring most frequently in the input image. The number of colors in the palette can be defined by the user of this operation with setPaletteSize(int).

Supported image types

The input image must implement RGB24Image, the output image must be of type Paletted8Image.

Usage example

The following code snippet uses the default settings with a palette of 256 entries.
 PopularityQuantizer quantizer = new PopularityQuantizer();
 quantizer.setInputImage(image);
 quantizer.setPaletteSize(256);
 quantizer.process();
 PixelImage quantizedImage = quantizer.getOutputImage();
 
Since:
0.11.0
Author:
Marco Schmidt
See Also:
  • Field Details

    • arbQuantizer

      private ArbitraryPaletteQuantizer arbQuantizer
    • paletteSize

      private int paletteSize
    • palette

      private Palette palette
    • doNotMap

      private boolean doNotMap
  • Constructor Details

    • PopularityQuantizer

      public PopularityQuantizer()
  • Method Details

    • createPalette

      public Palette createPalette()
      Description copied from interface: RGBQuantizer
      Return a Palette object with the list of colors to be used in the quantization process. That palette may be fixed or created specifically for a given input image.
      Specified by:
      createPalette in interface RGBQuantizer
      Returns:
      Palette object for destination image
    • determinePalette

      private Palette determinePalette() throws OperationFailedException
      Throws:
      OperationFailedException
    • getPaletteSize

      public int getPaletteSize()
      Returns the number of colors in the destination image. If output is paletted, this is also the number of entries in the palette.
      Returns:
      number of colors in the destination
      See Also:
    • map

      public int map(int[] origRgb, int[] quantizedRgb)
      Description copied from interface: RGBQuantizer
      This method maps a triplet of intensity values to its quantized counterpart and returns the palette index of that quantized color. The index values for the two arrays are taken from RGBIndex.
      Specified by:
      map in interface RGBQuantizer
      Parameters:
      origRgb - the three samples red, green and blue for which a good match is searched in the palette
      quantizedRgb - will hold the three samples found to be closest to origRgb after the call to this method
      Returns:
      int index in the palette of the match quantizedRgb
    • process

      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
      OperationFailedException
      WrongParameterException - if at least one of the input parameters was not initialized appropriately (values out of the valid interval, etc.)
    • setMapping

      public void setMapping(boolean newValue)
      Specifies whether this operation will map the image to the new palette (true) or not (false). The latter may be interesting if only the palette is required. By default, this operation does map.
      Parameters:
      newValue - map to new image (true) or just search palette (false)
    • setPaletteSize

      public void setPaletteSize(int newPaletteSize)
      Sets the number of colors that this operations is supposed to reduce the original image to.
      Parameters:
      newPaletteSize - the number of colors
      Throws:
      IllegalArgumentException - if the argument is smaller than 1 or larger than 256
      See Also: