Image formats supported by ShapeLogic

Until ShapeLogic's 1.0 release, the image processing algorithms where only running under ImageJ.

Now ShapeLogic's image processing algorithms have been decoupled from ImageJ. The idea is not to redo ImageJ's functionality but to make ShapeLogic more modular. All of ShapeLogic's current image processing algorithms only use very simple image properties so they should apply outside of ImageJ.

Not everything will work outside of ImageJ. The letter match example has a first step that is a skeletonize algorithm that comes with ImageJ. I you want to use the full letter match example outside ImageJ you will need another implementation of the skeletonize algorithm.

Main idea Interfaces SLImage and ImageOperation

Main idea was to abstract out a subset of the ImageProsessor and PlugInFilter into Java interfaces:

  • SLImage from ImageProsessor
  • ImageOperation from PlugInFilter

It is trivial implement them them in ImageJ and simple to do it in Java2D. When writing a image processing algorithm write an ImageOperation instead of a PlugInFilter.


This is a wrapper interface that contains very simple properties of an image.

In order to get a new image format to work transparently with ShapeLogic you need to make an adaptor pattern that for you image class to this interface.


This is a wrapper around a PlugInFilter. It is any operations that can change a SLImage.


PlugInFilterAdapter is the way to turn an ImageOperation into a PlugInFilter that can be run from ImageJ. Here is an example:

StreamVectorizer is an ImageOperation for vectorizing bitmaps and finding letters it it. It can be called with any SLImage, while StreamVectorizer_ is the letter matching example that you can use in ImageJ.

public class StreamVectorizer_ extends PlugInFilterAdapter {
        public StreamVectorizer_() {
                super(new StreamVectorizer());

Images classes in different image libraries

Here are some of the main Java image libraries order by complexity of the image classes.


ImageJ only have 4 different images.

Implemented by 4 subclasses of the ImageProcessor:

  • ByteProcessor 8 bits for gray and indexed images
  • ShortProcessor 16 bits for gray
  • FloatProcessor 32 bits for gray float
  • ColorProcessor for 32 bits ARGB

The focus is simplicity for the programmer. There is only one image layout for a given image type.


Java2D's main image format is BufferedImage. This is a very flexible class that can handle most non compressed layouts of a image that is loaded in a buffer.

JAI Java Advanced Imaging

JAI is a pretty complex image processing and rendering library. It can be used to handle big flow of operations and images that are too large to be loaded in memory at the same time.

Image formats that are supported

  • ImageProcessor from ImageJ
  • BufferedImage from Java2D

Image formats that might be supported later

  • TiledImage from JAI
  • OpImage from JAI

When to use ShapeLogic with ImageJ

ImageJ is a fantastic tool for image processing. Here are a few of its features:

  • A great GUI to experiment and work in
  • Lots of free plugins
  • It is the leading Java open source software image processing tool
  • Macro language to combine commands
  • Active user and developer community
  • Responsive mailing list
  • Very easy to program
  • It is free
  • The code is available and in the public domain

When not to use ShapeLogic with ImageJ

  • If you want to embed ShapeLogic in your application without adding ImageJ
  • Sometimes it is hard to separate ImageJ from the ImageJ GUI
  • You need to use some other library say Java2D or JAI