Marvin Image Processing Framework - Erosion plugin issue

Question

I have a problem with Erosion plugin in Marvin Image Processing Framework. I want to do erosion, but unfortunately, after that I'm getting no image in output. This is my code:

tempPlugin  = new Erosion();
boolean[][] m = new boolean[][] {
{true,true,true},
{true,true,true},
{true,true,true}
};
tempPlugin.setAttributes("matrix", m);
resultImage = MarvinColorModelConverter.rgbToBinary(resultImage, 127);
tempPlugin.process(resultImage, resultImage);
resultImage = MarvinColorModelConverter.binaryToRgb(resultImage);
resultImage.update();
imagePanelNew.setImage(resultImage);

I'm using Java JDK 1.7 and Marvin Framework 1.5.0 Of course, I've tried do the same with .jar file, without changes.

Somebody could help me, please?

Answer 1

There are some issues in your code. You are not using Marvin properly.

1. Loading plug-in

You must create an Erosion plug-in using MarvinPluginLoader:

tempPlugin  = MarvinPluginLoader.loadImagePlugin("org.marvinproject.image.morphological.erosion");

Thus, the Erosion plug-in and dependencies (since a plug-in might use other plug-ins) are properly loaded.

2. In the case of Erosion, you cannot use the same image object as input and output image

You must use two references, for instance cloning:

tempPlugin.process(resultImage.clone(), resultImage);

Example:

Below is presented a source code that achieves the same result presented in the Erosion Plug-in Page:

public class SimpleExample {

private MarvinImagePlugin tempPlugin;

public SimpleExample(){

    // 1. Load and set up plug-in.
    tempPlugin  = MarvinPluginLoader.loadImagePlugin("org.marvinproject.image.morphological.erosion");

    boolean[][] m = new boolean[][] {
    {true,true,true},
    {true,true,true},
    {true,true,true}
    };

    tempPlugin.setAttributes("matrix", m);

    // 2. Load image
    MarvinImage image = MarvinImageIO.loadImage("./res/erosion_in.png");
    MarvinImage resultImage = MarvinColorModelConverter.rgbToBinary(image, 127);

    // 3. Process and save image
    tempPlugin.process(resultImage.clone(), resultImage);
    resultImage = MarvinColorModelConverter.binaryToRgb(resultImage);
    resultImage.update();
    MarvinImageIO.saveImage(resultImage, "./res/erosion_out.png");
}

public static void main(String[] args) {
    new SimpleExample();
}

}