Class Brightness


public class Brightness extends LookupTableOperation
Adjusts the brightness of an image.

The brightness change is specified as a percentage value between -100 and 100. -100 will make the resulting image black, 0 will leave it unchanged, 100 will make it white.

Supported image types

Usage examples

Both examples make the input image 30 percent brighter.

If all you want is to create a new image with adjusted brightness from the image data of an existing image, simply use the static helper method:

PixelImage adjustedImage = Brightness.adjust(inputImage, 30);
This leaves the original image inputImage unchanged and allocates a second image object which is here assigned to the variable adjustedImage.

If you want more control over parameters, create your own Brightness object. You can then reuse image objects, e.g. to write the adjusted image data to the original image object:

 Brightness brightness = new Brightness();
 brightness.setInputImage(image);
 brightness.setOutputImage(image);
 brightness.setBrightness(30);
 brightness.process();
 // at this point, image will contain the adjusted image data,
 // the original data wil be overwritten 
 

Author:
Marco Schmidt
  • Field Details

    • brightness

      private int brightness
  • Constructor Details

    • Brightness

      public Brightness()
  • Method Details

    • adjust

      public static PixelImage adjust(PixelImage input, int percentage)
      This static helper method is more simple to use when all you need are the standard options.
      Parameters:
      input - the image to work on
      percentage - brightness modification, from -100 to 100
      Returns:
      a new image with adjusted brightness
    • createLookupTable

      private int[] createLookupTable(int numSamples, int brightness)
      Creates a lookup table that holds all new values for samples 0 to numSamples - 1.
    • process

      private void process(Paletted8Image in, Paletted8Image out)
    • 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 LookupTableOperation
      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.)
    • setBrightness

      public void setBrightness(int newBrightness)
      Sets the brightness adjustment value in percent (between -100 and 100).
      Parameters:
      newBrightness - the amount of change to be applied to the brightness of the input image
      Throws:
      IllegalArgumentException - if the argument is smaller than -100 or larger than 100