Posts Tagged JavaCvPro

Processing and Opencv 2.3.1 – How to install in win 7



The procedures to install opencv 2.3.1 libraries and JavaCvPro are explained in several sites. But I had many difficulties doing an installation in Windows 7, even following the step-by-step guides.

Then I would write a step-by-step procedure that is as simple as possible. The information sources that I used are :


This installation is working in windows 7 (32 and 64 bit) with Processing 1.5.  It was tested by me in 4 different pc. These are the steps:


1. Install the runtime components for Microsoft Visual C++ 2010:


2. Extract OpenCV-2.3.1-win-superpack.exe inside the root directory C:\. At the end, the opencv are in  C:\OpenCV\


3. Add the ddl path generated by opencv to windows 7 path. This can be made easily with a free program:  RapidEE. Download it from here and launch it.


4. Find the registry key PATH and click on it.




5. Click the right mouse button and choose add value in the menu. Add these values:

  • C:\opencv\build\x64\vc10\bin\
  • C:\opencv\build\x64\vc10\lib\
  • C:\opencv\build\common\tbb\intel64\vc10\

If the win7 32bit version the directory are with x86 instead of x64. For 32bit version add also C:\opencv\build\common\tbb\ia32\vc10\




6. Download the JavaCvPro library (version 0.3) here.


7. Extract and copy all in the Processing library directory: Processing /Mode/java/libraries


8. Download the last version of binary JavaCV  library here (today is


9. Extract and copy all in the Processing library directory: Processing /Mode/java/libraries


10. Create a directory called library inside the javacv-bin directory and put all the file (not the sample directory) inside this new library directory


11. Rename the library javacv-bin extracted with this name: javacv


12. Download the last version of the binary Javacpp library here  ( today is


13. Extract and copy all in the Processing library directory: Processing /Mode/java/libraries


10. Create a directory called library inside the javacpp-bin directory and put all the file (not the sample directory) inside this new library directory


11. Rename the library javacpp-bin with this name: javacpp



If all the steps are succeeded, it is done. Now you can start Processing and test this simple program (take from here):

import com.googlecode.javacv.*;
import com.googlecode.javacv.cpp.*;

import monclubelec.javacvPro.*;

OpenCV opencv; // déclare un objet OpenCV principal

void setup(){ // fonction d'initialisation exécutée 1 fois au démarrage

        opencv = new OpenCV(this); // initialise objet OpenCV à partir du parent This
        opencv.allocate(320,240); // crée le buffer image de la taille voulue


void  draw() { // fonction exécutée en boucle



It is very important to include also the javacv and javacpp libraries. In the documentation this is not required, but in my experience, without these libraries, the program doesn’t work.



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Processing and Opencv 2.3.1 – Introduction

To build a robot that draws portraits I need to have a good supply of tools for image processing. The best open source libraries available are the opencv that I would use with Processing.

Unfortunately opencv are available in C + + and python, but not in Java that is the language used in Processing. Luckily some guys  have built some wrappers that allow to use opencv with Processing.


Opencv processing library

The most famous library is this: which is very well documented. Its installation is simple and works well. But this library  supports only a few commands opencv and doesn’t provide access to thousands of opencv functions.It use QuickTime to perform functions that use the webcam. The commands supported are the most important, however, it is not enough.It allows to write code using opencv in a very simple way, making the primitives opencv a part of Processing language.

For example this is the capture()  function that allocates and initializes resources for reading a video stream from a camera.
OpenCV opencv; //opecv object

void setup() {
size( 320, 240 ); //window size
opencv = new OpenCV( this ); // opencv object
opencv.capture( width, height ); // open video stream

void draw() {; // grab frame from camera
image( opencv.image(), 0, 0 ); } // and display image

not bad! only 10 rows to display the webcam image. The opencv functions are very easy with this library, but the opencv supported is only the 1.0 and the number of the function is very low.



Luckily there is another library that allows to use the last version of the opencv, the 2.3.1: JavacvPro.
The documentation for this library is only in French.I understandFrench well, so I have no problems! 🙂

This library implements natively over 100 opencv functions, making them part of the language Processing. In addition it use the library GSVideo which is the official video library for the version 2.0 of Processing.

The use of the library is very simple. This is an example of syntax of the function of edge detection of the original opencv:

cvCanny (opencv_core.CvArr image, opencv_core.CvArr edges, double threshold1, double threshold2, int aperture_size)

this is the corresponding on JacaCvPro in Processing:

canny (PImage image)

The library takes care of the rest! not bad right?  But how does work the processing wrapping in opencv? Opencv is a library written in C + +, Processing works in Java.
JavaCvPro uses another library , javacv, which implements almost all the OpenCV functions directly in Java. Moreover, there is another library, javacpp, which implemets the real link between Java and C++.

So, the chain among libraries is:

Processing —> JavaCvPro —> javacv —> javacpp- –> OpenCV

Difficult? No, easy!

In the next post I show how install opencv and JavaCvPro in windows 7 environment.

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