Package io.scanbot.imagefilters

Class GrayscaleFilter

  • All Implemented Interfaces:
    android.os.Parcelable 
    
public final class GrayscaleFilter
extends ParametricFilter

    Converts color images to grayscale, optionally applying autocontrast.

    • Nested Class Summary

      Nested Classes 
      Modifier and Type Class Description

    • Constructor Summary

      Constructors 
      Constructor Description
      GrayscaleFilter(Float borderWidthFraction, Float blackOutliersFraction, Float whiteOutliersFraction)

    • Enum Constant Summary

      Enum Constants 
      Enum Constant Description

    • Method Summary

      Modifier and Type Method Description
      final Float getBorderWidthFraction() Ignore this fraction of pixels at the edge of the image when calculating statistics.
      final Float getBlackOutliersFraction() Clip this fraction of the darkest pixels in operations such as autocontrast.
      final Float getWhiteOutliersFraction() Clip this fraction of the brightest pixels in operations such as autocontrast.

      • Methods inherited from class java.lang.Object

        clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

    • Constructor Detail

      • GrayscaleFilter

        GrayscaleFilter(Float borderWidthFraction, Float blackOutliersFraction, Float whiteOutliersFraction)

    • Method Detail

      • getBorderWidthFraction

         final Float getBorderWidthFraction()

        Ignore this fraction of pixels at the edge of the image when calculating statistics.

        Pixels at the edge of the image typically have poor statistics. Ignoring them and using only the inner pixels when calculating certain statistics can substantially improve the quality of the result.

        The value must be less than 0.5 but usually good values are between 0 and 0.15.

      • getBlackOutliersFraction

         final Float getBlackOutliersFraction()

        Clip this fraction of the darkest pixels in operations such as autocontrast.

        Increasing the range of middle gray levels at the expense of the brightest and darkest levels may improve the overall contrast and quality of the result.

        Sum of blackOutliersFraction and whiteOutliersFraction must be less than 1 but usually good values for the parameters do not exceed 0.05;

      • getWhiteOutliersFraction

         final Float getWhiteOutliersFraction()

        Clip this fraction of the brightest pixels in operations such as autocontrast.

        Increasing the range of middle gray levels at the expense of the brightest and darkest levels may improve the overall contrast and quality of the result.

        Sum of blackOutliersFraction and whiteOutliersFraction must be less than 1 but usually good values for the parameters do not exceed 0.05;