becker.xtras.imageTransformation
Interface ITransformations

All Known Implementing Classes:

SampleTransformations

public interface ITransformations

Classes implementing the ITransformations interface can be used with the ImageTransformerGUI class to transform grey-scale images. ITransformations instances do the actual work of transforming the images: brightening, rotating, flipping, etc. The GUI finds the available transformations by calling getTransformationNames and makes a button for each name in the returned array. The performTransformation method is called each time one of these buttons is clicked by the user with the appropriate transformation name passed as a parameter.

Each pixel ("picture element") in the image to be transformed is represented by an integer between 0 and 255. A small value represents a dark color and a larger value represents a light color. These integers are stored in a two- dimensional array. The value in pixels[0][0] represents the upper- left corner of the image. By rearranging the order of these values the image can be rotated or flipped. By changing the magnitude of each value the image can be lighted or darkened.

A class implementing ITransformations would typically be structured like this:

    public class MyTransformations extends Object implements ITransformations
    {   private int[][] pixels;
        private ViewList views = new ViewList();
        
        public MyTransformations() {  ... }

        public void setPixels(int[][] newPix)
        {  this.pixels = newPix;
           this.views.updateAllViews();
        }

        public int[][] getPixels()
        {  return this.pixels;
        }

        public void performTransformation(String transformationName)
        { ...
          this.views.updateAllViews();
        }
    
        public String[] getTransformationNames()
        {  return new String[] {"Darken", "Brighten", "FlipX", "FlipY", "Reset"};
        }

        public void addView(IView aView)
        {  this.views.addVIew(aView);
        }
    }
 

It is up to the implementor whether transformations are cumulative (each transformation changes the pixels array) or independent (the transformed image is copied into a new array that is returned, leaving pixels untouched).

Please see the package description for a more in-depth discussion of using this class.

Author:

Michael DiBernardo and Byron Weber Becker

Method Summary

void	addView(IView aView) Add a view (graphical user interface) to the image transformer.
int[][]	getPixels() Get the image that was transformed.
String[]	getTransformationNames() A array filled with the names of the transformations implemented by this class.
void	performTransformation(String transformationName) Perform the transformation indicated.
void	setPixels(int[][] newPix) Set the image to be transformed to a new set of pixels.

Method Detail

setPixels

void setPixels(int[][] newPix)

Set the image to be transformed to a new set of pixels.

Parameters:

newPix - The new image to be used for subsequent transformations.

getPixels

int[][] getPixels()

Get the image that was transformed.

Returns:

The pixels representing the image.

performTransformation

void performTransformation(String transformationName)

Perform the transformation indicated.

Parameters:

transformationName - The name of the transformation to perform. Must be one of the transformation names returned by getTransformationNames.

getTransformationNames

String[] getTransformationNames()

A array filled with the names of the transformations implemented by this class.

Returns:

The array of transformation names.

addView

void addView(IView aView)

Add a view (graphical user interface) to the image transformer. The view's updateView method must be called each time the transformer's state changes.