Copyright (c) 2002, Junzo SATO. All rights reserved.

Java Photo Editor 2002

Java Photo Editor is a graphics application which has some mouse operative tools for graphics painting and region-of-interest selection. Because Java Photo Editor has interface to Mathematica J/Link, collaborative work of the image process between Java Photo Editor and Mathematica is enabled.

Junzo SATO

Medical Information Technology & Administration Planning, Kumamoto University Hospital

jsato@fc.kuh.kumamoto-u.ac.jp
http://fc.kuh.kumamoto-u.ac.jp/~jsato/

Nov 4th 2002
Nov 3rd 2002
Nov 1st 2002
Oct 24th 2002

Part One: Java Graphics

InstallJava

JLink is installed.

For Sun's j2sdk user on PC, setting CommandLine option should be required.

<<JLinkProgramming`JavaSwing`

JavaSwing package is a wrapper for JFC Swing classes.

Getting Java Image

ImageIcon is created.

Java Image object is received through the ImageIcon.

The size of the image is retrieved.

<<JLinkProgramming`JavaPhotoEditor`

JavaPhotoEditor package is loaded.

Java Image To Graphics

Pixels in the Java image can be retrieved by using java.awt.image.PixelGrabber. A pixel in Java is defined by 4 byte integer in the form of ARGB. GrabPixels[ ] decompose the Java image into a matrix of {R,G,B}s.

Matrix of colors GrabPixels[ ] has returned can be shown as Graphics object by converting it into a RasterArray[ ].

Graphics To Java Image

Graphics object g constructed using RasterArray[ ] or Raster[ ] is converted to the Java Image by ToJavaImage[ ].

Then the Java Image ji is shown again as Graphics.

A Graphics object is not always constructed by RasterArray/Raster. For example, Plot[ ] has graphics primitive(s) such as Line[ ](s.).

In this example a Line[ ] is used to generate Graphics.

By putting a string "pl" to the ToJavaImage[ ], the Plot[ ] is converted to the Java Image.

The rasterized image data is shown by ShowJavaImage[ ].

Part Two: Java Photo Editor

Creating JPEFrame

The Java class JPEFrame is a main entry of the Java Photo Editor application. New instantce of JPEFrame is created. The default image in the resource of javaphotoeditor is painted at first.

JPEFrame has a JPEPanel which is a subclass of JLink's class MathGraphicsJPanel.

The image drawn on the panel is stored inside JPEPanel. It is accessible from Mathematica by calling getSourceImage() method.

Loading Image

Loading Java Image

The javaImage which is created by previous example is set to Java Photo Editor.

Loading Image From URL

Loading image data on the web is possible by specifying URL.

Loading Image From File

An image file on the local disk is possible by specifying File object.

Loading Image From Path

An image is loaded by specifying full path of the file.

Using setMathCommand( )

command

A function which creates Graphics3D is defined.

Showing graphics operation is defined as a string.

Converting it to an expression and evaluation makes output graphics.

setMathCommand( )

JPEFrame is disposed.

New JPEFrame whose panel has specified width and height is created. Note that 4 pixels on each side are added for insets used by JLink.

JPEPanel on the frame is received.

Panel size is shown.

The method setMathCommand[ ] evaluates command string by making it to an expression.

Panel's preferred size is adjusted and the frame is shown.

Note that panel's size is changed after showing the frame.

Panel's preferred size is set. It has no insets of 4 pixels.

Menu Item "File/Load..."

Choosing a command "File/Load..." opens a dialog to specify image source by URL or File path.

Load Image dialog is shown.

The specified image is loaded to Java Photo Editor.

Region Of Interest Bounds --- Marquee Rect

Painting some shapes and texts are done using painting tool. The region of interest bounds on the image can be selected by the marquee rect tool.

Rectangular area selected by the marquee tool is obtained.

Region Of Interest --- Area Selection

Selected area, created by moving a mouse clockwise, is returned as Java's Polygon object.

Bounds of the selected area is returned.

Part Three: Digital Image Processing

ImageData

Digital Image Processing package is loaded.

A sample image file is loaded by ImageRead[ ] function. ImageData object is returned.

The data is shown.

Digital Image Processing package has many image filtering functions. Some of them is used.

BufferedImage

ImageProcessing`BufferedImage` has fine tuned functions for converting ImageData from/to Java BufferedImage. Java Photo Editor uses this function internally when the user wants to collaborate with it.

<<JLinkProgramming`JavaPhotoEditor`DIPSupportJ`

JavaImageToImageData

A package to make Java Photo Editor collaborate with Digital Image Processing package is loaded.

Collaboration With Java Photo Editor

Marquee Rect

ImageData is created by JavaImageToImageData[ ] function.

The image previously clipped by the marquee rect tool is shown again through the ImageData.

An image processing operation is applied to the ImageData.

The result ImageData is shown.

Area Selection

The selected area by using area selection tool is now returned as an ImageData.

The same image is shown again through this ImageData.

Function to apply filter operation to the region of interest is defined.

The Polygon[ ] poly derived from the Java Photo Editor is used as the region of interest in this case.

The result ImageData is shown.

ImageDataToJavaImage

The filtered image data is converted to the Java Image and then drawn on the Java Photo Editor's panel.

Part Four: Menu Commands

Menu Bar

The menu bar in the frame is received.

Number of menus currently added in the menu bar is shown.

Informations about menus are retrieved.

Adding New Menu

New menu is created and added to the menu bar.

Menu item is added to the menu.

Listener class for menu action is loaded.

A command handler is defined and is set to the listener.

The listener itself is attached to the menu item.

BEFORE USING ANY MENU COMMAND DEFINED IN MATHEMATICA, SHARING FRONTEND SHOULD BE STARTED.

Now clicking a menu item makes Mathematica print a string. Because this 'calculation' is done very fast, it might be impossible to see the change of frame's title.

The definition of the handlerItemFilter[ ] is changed.

Clicking a menu item invokes this command handler.

Doing More With Menu

The definition of menu command handler is changed so that it receives the marquee rect and convert rectangular image to the ImageData to evaluate TryFilter[ ] function in newly created Notebook.

After evaluation, new Notebook shows the result.

Quit

Sharing FrontEnd is halted.

Installed link is closed.