ShapeLogic Scala

ShapeLogic Scala is a generic computer vision library with cross-platform GUI. You write your image processing algorithm once, and it will work for images based on byte, short, float and double.

It has standard image processing algorithms like: Invert, threshold, edge detection, segmentation, skeletonize, edge tracer, vectorizer, point and line annotation all written in generic idiomatic Scala.

Getting Started

Include ShapeLogic as library in your SBT project

"org.shapelogicscala" %% "shapelogic" % "0.9.0"

Versions available for Scala 2.11 and 2.12

Work with ShapeLogic source locally

clone git https://github.com/sami-badawi/shapelogic-scala.git
cd shapelogic-scala
sbt compile
sbt test

Start the ShapeLogic JavaFX GUI

sbt stage
or on Windows

ShapeLogic Scala has a simple JavaFX GUI, it can:

  • Load and save images
  • Undo and image info
  • Invert
  • Threshold, background and foreground selection
  • Sobel edge detection
  • Edge crawler with vectorizer and feature extraction for points and lines
  • Segmentation
  • Morphology: Skeletonize, outline, dilate, erode, open and close
  • To gray scale, fill black and white
  • Color channel chooser, channel swapper


  • Version 0.9.0
  • It is pretty simple to write image operations and add them to GUI
  • In alpha, but getting more stable
  • ShapeLogic Scala project site
  • GitHub project
  • Unit test using ScalaTest
  • Google group

Short Term Goals

  • Particle analyzer and line finder as start of OCR system
  • Output annotated points, lines and polygons in json format
  • Work well with Java image processing libraries like: ImageJ, BoofCV and OpenCV Java

Long Term Goals

ShapeLogic Scala goal is be a framework for object recognition using a hybrid approach to A.I. combining machine learning and symbolic A.I. Using some of the following techniques:

  • Machine learning
    • Convolutional neural network
    • Logistic regression, Naive Bayes or random forest
    • Baysian network / graphical model
  • Symbolic artificial intelligence
    • Lisp like tree search / lazy stream
    • Logic programming
    • RDF or knowledge graph
    • Database

First example will be OCR, optical character recognition for a page of text. It is a solved but nontrivial problem.

Convolutional Neural Network

The success of Convolutional Neural Network is indisputable. ShapeLogic intend to use CNN for lower level pattern matching not for end to end solutions. Either using TensorFlow’s Java interface, Deeplearning4j or hand programmed pattern matches.


ShapeLogic Scala has a unified generic image class BufferImage that is mainly a buffer.

If you want to program your own image operations here are 5 base image operations you can start from:

Generic Image What is the Big Deal

There are a lot of challenges with creating a generic image class like BufferImage:

  • Bytes are signed in Scala and Java but unsigned for images
  • Primitive numeric types are not a subclass of anything
  • Byte needs to be promoted to integers, while float do not, normal generic classes will not do this
  • Some sort of dependent types are needed which can be accomplished using type level programming
  • Type classes can be used to define number, but they do not play well type level programming
  • The image class need to be specialized to avoid boxing of primitive operation

ShapeLogic History

ShapeLogic Java was started in 2007 as a Java image processing library and library for functional programming techniques in Java. Functional programming now has better implementations in Java 8 and Scala. ShapeLogic Scala was started in 2016 and ports parts of ShapeLogic Java.

Image IO and Dependencies

The goal is to keep library dependencies for ShapeLogic low. Currently the images loaders are using javax.imageio and JavaFX. They are only part of Oracle JDK not on OpenJDK.

  • Stardard Git and SBT Scala project
  • Dependencies on

Example of Running Command Line Scripts

sbt 'run-main org.shapelogic.sc.script.Threshold -i "image/rgbbmwpng.png" -t 10 -o "image/out.png"'
target/universal/stage/bin/shapelogic -main "org.shapelogic.sc.script.Threshold" -- -i image/440px-Lenna.png

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