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Trying to draw a graph but getting Null on weigths

I'm trying to create an image file of a graph with vertices,edges and weigths with JgraphX and mxGraph.
I'm new to this thing of JGraph and stuff and found a tutorial to do this.
But I can't understand why when it creates the image, it shows the vertices and edges good but the weights are "Null".
I'll post the code below together with a image.
import com.mxgraph.layout.mxCircleLayout;
import com.mxgraph.layout.mxIGraphLayout;
import com.mxgraph.util.mxCellRenderer;
import org.jgrapht.ext.JGraphXAdapter;
import org.jgrapht.graph.DefaultDirectedGraph;
import org.jgrapht.graph.DefaultDirectedWeightedGraph;
import org.jgrapht.graph.DefaultEdge;
import org.jgrapht.*;
import org.jgrapht.graph.DefaultUndirectedWeightedGraph;
import org.jgrapht.traverse.BreadthFirstIterator;
import javax.imageio.ImageIO;
import java.awt.*;
import java.awt.image.BufferedImage;
import java.io.File;
import java.io.IOException;
public class JgraphTest{
DefaultDirectedWeightedGraph<String, DefaultEdge> g = new DefaultDirectedWeightedGraph<>(DefaultEdge.class);
BreadthFirstIterator bfs;
public void crearGrafo(){
g.addVertex("Ninja1");
g.addVertex("Ninja2");
g.addVertex("Ninja3");
g.addVertex("Ninja5");
g.addVertex("Ninja8");
g.addEdge("Ninja1","Ninja2");
g.addEdge("Ninja2","Ninja1");
g.addEdge("Ninja8","Ninja3");
g.addEdge("Ninja3","Ninja5");
g.setEdgeWeight("Ninja1","Ninja2",12);
g.setEdgeWeight("Ninja2","Ninja1",2);
g.setEdgeWeight("Ninja8","Ninja3",10);
}
public void mostrarGrafo() throws IOException {
JGraphXAdapter<String, DefaultEdge> graphXAdapter = new JGraphXAdapter<>(g);
mxIGraphLayout layout = new mxCircleLayout(graphXAdapter);
layout.execute(graphXAdapter.getDefaultParent());
BufferedImage image = mxCellRenderer.createBufferedImage(graphXAdapter, null, 2, Color.white, true, null);
File imgFile = new File("src/graph.jpg");
ImageIO.write(image, "JPG",imgFile );
}
}
Image created after executing the algorithm
Thank you everyone and I hope I didn't miss any information, please let me know if I forgot to post something.

Does Apache POI API support PPTX2PNG conversion (in java programs) for pptx generated by LibreOffice Impress?

I am trying to convert the pptx to png images using apache-poi in java but it doesn't work with pptx generated by LibreOffice Impress (works fine with others ) and there is no exception thrown.
The resulting images I get are just the background with out the text content of the pptx.
Please see the links for the results.
The resulting image
Screen shot of Actual pptx slide
This is the basic code I got :
package com.preview;
import java.awt.Dimension;
import java.awt.Graphics2D;
import java.awt.geom.AffineTransform;
import java.awt.geom.Rectangle2D;
import java.awt.image.BufferedImage;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.util.List;
import org.apache.poi.xslf.usermodel.XMLSlideShow;
import org.apache.poi.xslf.usermodel.XSLFSlide;
public class PptxToPng {
public static void main(String[] args) throws IOException {
// TODO Auto-generated method stub
FileInputStream is = new FileInputStream("~/Downloads/pptx/SamplePPTX.pptx");
XMLSlideShow ppt = new XMLSlideShow(is);
is.close();
double zoom = 2;
AffineTransform at = new AffineTransform();
at.setToScale(zoom, zoom);
Dimension pgsize = ppt.getPageSize();
List<XSLFSlide> slide = ppt.getSlides();
BufferedImage img = new BufferedImage((int)Math.ceil(pgsize.width*zoom),
(int)Math.ceil(pgsize.height*zoom), BufferedImage.TYPE_INT_RGB);
Graphics2D graphics = img.createGraphics();
graphics.setTransform(at);
graphics.fill(new Rectangle2D.Float(0, 0, pgsize.width, pgsize.height));
// Draw first page in the PPTX. First page starts at 0 position
slide.get(0).draw(graphics);
FileOutputStream out = new FileOutputStream("~/Downloads/pptx/converted.png");
javax.imageio.ImageIO.write(img, "png", out);
out.close();
ppt.close();
System.out.println("DONE");
}
}

poi-ooxml-3.15.jar comes with a tool called PPTX2PNG. It can be found in the package org.apache.poi.xslf.util
Execute it eg with parameters -scale 1 -format jpg pptx-file.pptx and it should write an image file to the same directory as the origin pptx file.
BTW: despite the name, it can write to png, jpg and gif formats.

Need help to remove exception in my java graphics code

I am developing an application in swing which has 5 tabs with following 5 operations on an image :No Operation ,Color Convert ,Affine Transform ,Convolve and Look Up.
Here is the code :
import java.awt.color.ColorSpace;
import java.awt.geom.AffineTransform;
import java.awt.image.AffineTransformOp;
import java.awt.image.BufferedImage;
import java.awt.image.ColorConvertOp;
import java.awt.image.ConvolveOp;
import java.awt.image.Kernel;
import java.awt.image.LookupOp;
import java.awt.image.LookupTable;
import java.awt.image.ShortLookupTable;
import java.io.File;
import java.io.IOException;
import javax.imageio.ImageIO;
import javax.swing.ImageIcon;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JTabbedPane;
import javax.swing.SwingUtilities;
import javax.swing.UIManager;
public class ImageProcessing extends JFrame{
BufferedImage source;
public static void main(String args[])
{
try {
UIManager.setLookAndFeel("javax.swing.plaf.nimbus.NimbusLookAndFeel");
} catch (Exception e1){e1.printStackTrace();}
SwingUtilities.invokeLater(new Runnable(){public void run(){new ImageProcessing();}});
}
public ImageProcessing() {
// TODO Auto-generated constructor stub
super("Image Processing");
setSize(600,400);
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
try
{
source=ImageIO.read(new File("src/abc.jpg"));
}catch(IOException e){System.out.println("Exception Here :"+e);}
JTabbedPane jtp=new JTabbedPane();
buildNoOpTab(jtp);
buildAffineTransformOpTab(jtp);
buildColorConvertOpTab(jtp);
buildConvolveOpTab(jtp);
buildLookUpOpTab(jtp);
//buildRescaleOpTab(jtp);
add(jtp);
setVisible(true);
}
private void buildNoOpTab(JTabbedPane jtp)
{
jtp.add("No Op",new JLabel(new ImageIcon(source)));
}
private void buildAffineTransformOpTab(JTabbedPane jtp)
{
BufferedImage dst;
AffineTransform transform=AffineTransform.getScaleInstance(0.5, 0.5);
AffineTransformOp op=new AffineTransformOp(transform, AffineTransformOp.TYPE_BILINEAR);
dst=op.filter(source, null);
jtp.add("AffineTransform",new JLabel(new ImageIcon(dst)));
}
private void buildColorConvertOpTab(JTabbedPane jtp)
{
BufferedImage dst = null;
ColorSpace clr=ColorSpace.getInstance(ColorSpace.CS_GRAY);
ColorConvertOp op=new ColorConvertOp(clr,null);
dst=op.filter(source,dst);
jtp.add("Color Convert",new JLabel(new ImageIcon(dst)));
}
private void buildConvolveOpTab(JTabbedPane jtp) {
BufferedImage dst = null;
float sharpen[] = new float[] {
0.0f, -1.0f, 0.0f,
-1.0f, 5.0f, -1.0f,
0.0f, -1.0f, 0.0f
};
Kernel kernel = new Kernel(3, 3, sharpen);
ConvolveOp op = new ConvolveOp(kernel);
dst = op.filter(source, null);
jtp.add("Convolve", new JLabel(new ImageIcon(dst)));
}
private void buildLookUpOpTab(JTabbedPane jtp)
{
BufferedImage dst=null;
short[] data=new short[256];
for(int i=0;i<256;i++)
data[i]=(short)(255-i);
LookupTable lkp=new ShortLookupTable(0,data);
LookupOp op=new LookupOp(lkp,null);
dst=op.filter(source, null);
jtp.add("Look Up",new JLabel(new ImageIcon(dst)));
}
}
There is some problem in the buildLookUpOpTab as removing this method application works fine.
Here is the exception which I am getting:
Exception in thread "AWT-EventQueue-0" java.lang.IllegalArgumentException:
Number of color/alpha components should be 3 but length of bits array is 1
at java.awt.image.ColorModel.<init>(ColorModel.java:336)
at java.awt.image.ComponentColorModel.<init>(ComponentColorModel.java:273)
at java.awt.image.LookupOp.createCompatibleDestImage(LookupOp.java:413)
at java.awt.image.LookupOp.filter(LookupOp.java:153)
at ImageProcessing.buildLookUpOpTab(ImageProcessing.java:108)
at ImageProcessing.<init>(ImageProcessing.java:49)
at ImageProcessing$1.run(ImageProcessing.java:30)
at java.awt.event.InvocationEvent.dispatch(InvocationEvent.java:251)
at java.awt.EventQueue.dispatchEventImpl(EventQueue.java:701)
at java.awt.EventQueue.access$000(EventQueue.java:102)
at java.awt.EventQueue$3.run(EventQueue.java:662)
at java.awt.EventQueue$3.run(EventQueue.java:660)
at java.security.AccessController.doPrivileged(Native Method)
at java.security.ProtectionDomain$1.doIntersectionPrivilege(ProtectionDomain.java:76)
at java.awt.EventQueue.dispatchEvent(EventQueue.java:671)
at java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:244)
at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:163)
at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:151)
at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:147)
at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:139)
at java.awt.EventDispatchThread.run(EventDispatchThread.java:97)
Can anyone tell me what is the problem in that method?

The LookupOp.filter method says that:
Performs a lookup operation on a BufferedImage. If the color model in the source image is not the same as that in the destination image, the pixels will be converted in the destination. If the destination image is null, a BufferedImage will be created with an appropriate ColorModel. An IllegalArgumentException might be thrown if the number of arrays in the LookupTable does not meet the restrictions stated in the class comment above, or if the source image has an IndexColorModel.
Since you are filtering a BufferedImage created from using ImageIO.read, the color model that the image will have will definitely not be IndexColorModel, since JPEGImageReader (which actually created the BufferdImage from the file) does not support IndexColorModel - in the olden days, JPEGs used the DirectColorModel
Have a look at the answer on this thread on how to read a JPEG file and use a different color model:
Unable to read JPEG image using ImageIO.read(File file)

You need to remove alpha channel from your image before using any filter on it. To make your code working, change:
try
{
source=ImageIO.read(new File("src/abc.jpg"));
} catch(IOException e){System.out.println("Exception Here :"+e);}
with this:
try
{
BufferedImage src = ImageIO.read(new File("abc.jpg"));
int w = src.getWidth();
int h = src.getHeight();
source = new BufferedImage(w, h, BufferedImage.TYPE_INT_RGB);
Raster raster = src.getRaster().createChild(0, 0, w, h, 0, 0,
new int[] {0, 1, 2});
source.setData(raster);
}catch(IOException e){System.out.println("Exception Here :"+e);}
The above code creates a new buffered image in RGB mode and set the RGB data of original image to new buffered image ignoring the alpha values. But in case your original image contains completely transparent spots then it will become black spots in new buffered image.

Chroma key effect in Java

I also need to find a library which allows to implement the "chroma key" effect in Java. The video contains some part in green color, which is replaced which a picture during the rendering in order to create a new video.
I am linking my question with a similar question which was already answered but with uncomplete answer (Looking for Chromakey library in Java). Could you please specify how did you do to have something up and working so quickly? I have been unsuccessful for some months fighting against the same issue.
c00kiemon5ter pointed several resources:
JavaCV
JAI (Java Advanced Imaging API)
Java Image Processing Cookbook
Which one did work for you?

JavaCV contains lots of methods to process video streams.
This code should get you started: http://tech.groups.yahoo.com/group/OpenCV/message/59118 but it's probably too slow in Java. Try this approach:
Create a filter which turns all the green pixels into a mask (look for things that "select by color").
Use the mask to copy the background image into the video.

I would like to contribute with a piece of code which gave me quite good results. I wonder if I used the classes and methods that Aaron Digulla suggested.
Please note that in this case my video has black background, that is why I am replacing the black color with the background image. I expect to obtain better results when I can edit the video to have green background, because black color is more likely to be used within the video main characters and replacing wrong pixels causes a quite awful effect.
--
package transparentvideo;
import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.Component;
import java.awt.Container;
import java.awt.Dimension;
import java.awt.Graphics2D;
import java.awt.Image;
import java.awt.Rectangle;
import java.awt.Toolkit;
import java.awt.image.BufferedImage;
import java.awt.image.FilteredImageSource;
import java.awt.image.ImageFilter;
import java.awt.image.ImageProducer;
import java.awt.image.RGBImageFilter;
import java.io.File;
import javax.media.Manager;
import javax.media.Player;
import javax.swing.ImageIcon;
import javax.swing.JComponent;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
public class TransparentVideo
{
Player mediaPlayer;
JFrame invisibleFrame;
JFrame visibleFrame;
JLabel videoScreen;
JPanel offScreenVideo;
String backgroundImageFile="nature.jpg";
String videoFile="girl.mov";
public TransparentVideo()
{
invisibleFrame = new JFrame();
invisibleFrame.setSize(400, 400);
Container container=invisibleFrame.getContentPane();
offScreenVideo = getvidComp();
offScreenVideo.setPreferredSize(container.getSize());
offScreenVideo.setVisible(true);
container.add(offScreenVideo);
invisibleFrame.setVisible(true);
visibleFrame=new JFrame();
visibleFrame.setSize(container.getSize());
visibleFrame.setLocationRelativeTo(null);
videoScreen = new JLabel();
visibleFrame.getContentPane().add(videoScreen);
visibleFrame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
visibleFrame.setVisible(true);
invisibleFrame.setVisible(false);
try
{
while(true)
{
if(mediaPlayer.getState()==Player.Started)
reDraw();
Thread.sleep(100);
}
}
catch (Exception ex)
{
System.out.println(ex.getMessage());
}
}
public void reDraw()
{
BufferedImage bi=new BufferedImage(videoScreen.getWidth(), videoScreen.getHeight(),
BufferedImage.TYPE_INT_ARGB);
bi.getGraphics().drawImage(new ImageIcon(backgroundImageFile).getImage(), 0 , 0 ,
videoScreen.getWidth(), videoScreen.getHeight(), null);
BufferedImage screenShot = createImage((JComponent) offScreenVideo,
new Rectangle(invisibleFrame.getBounds()));
Image im = makeColorTransparent(new ImageIcon(screenShot).getImage(), Color.BLACK);
bi.getGraphics().drawImage(im, 0 ,0 , videoScreen.getWidth(), videoScreen.getHeight(), null);
videoScreen.setIcon(new ImageIcon(bi));
}
public static BufferedImage createImage(Component component, Rectangle region)
{
if (!component.isDisplayable()) {
Dimension d = component.getSize();
if (d.width == 0 || d.height == 0) {
d = component.getPreferredSize();
component.setSize(d);
}
layoutComponent(component);
}
BufferedImage image = new BufferedImage(region.width, region.height, BufferedImage.TYPE_INT_RGB);
Graphics2D g2d = image.createGraphics();
if (!component.isOpaque())
{
g2d.setColor(component.getBackground());
g2d.fillRect(region.x, region.y, region.width, region.height);
}
g2d.translate(-region.x, -region.y);
component.paint(g2d);
g2d.dispose();
return image;
}
public static void layoutComponent(Component component)
{
synchronized (component.getTreeLock())
{
component.doLayout();
if (component instanceof Container)
{
for (Component child : ((Container) component).getComponents())
{
layoutComponent(child);
}
}
}
}
public JPanel getvidComp()
{
Manager.setHint(Manager.LIGHTWEIGHT_RENDERER,true);
try
{
mediaPlayer = Manager.createRealizedPlayer(new File(videoFile).toURL());
mediaPlayer.realize();
mediaPlayer.prefetch();
JPanel video=new JPanel(new BorderLayout());
video.add(mediaPlayer.getVisualComponent()) ;
mediaPlayer.start();
return video;
}
catch( Exception d)
{
return null;
}
}
public static Image makeColorTransparent( Image im, final Color color)
{
ImageFilter filter = new RGBImageFilter()
{
public int markerRGB = color.getRGB() | 0xFF000000;
public final int filterRGB(int x, int y, int rgb)
{
Color c=new Color(rgb);
int red=c.getRed();
int green=c.getGreen();
int blue=c.getBlue();
//if(red<140 && green<140 && blue<140)
{
int alpha=Math.max(Math.max(red , green), Math.max(green, blue))*3;
c=new Color(red , green , blue , alpha>255 ?255 :alpha );
}
return c.getRGB();
}
};
ImageProducer ip = new FilteredImageSource(im.getSource(), filter);
return Toolkit.getDefaultToolkit().createImage(ip);
}
public static void main(String[] args) {
new TransparentVideo();
}
}

Does anyone have an example of Apache POI converting PPTX to PNG

Does anyone know of a good example of converting a PPTX powerpoint presentation to some form of image? PNG/GIF/etc?
I can do it for a PPT but looking for a PPTX conversion example
Thanks

In the meantime it works (... copied it from there):
import java.awt.Color;
import java.awt.Dimension;
import java.awt.Graphics2D;
import java.awt.geom.AffineTransform;
import java.awt.geom.Rectangle2D;
import java.awt.image.BufferedImage;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import org.apache.poi.xslf.usermodel.XMLSlideShow;
import org.apache.poi.xslf.usermodel.XSLFSlide;
public class PptToPng {
public static void main(String[] args) throws Exception {
FileInputStream is = new FileInputStream("example.pptx");
XMLSlideShow ppt = new XMLSlideShow(is);
is.close();
double zoom = 2; // magnify it by 2
AffineTransform at = new AffineTransform();
at.setToScale(zoom, zoom);
Dimension pgsize = ppt.getPageSize();
XSLFSlide[] slide = ppt.getSlides();
for (int i = 0; i < slide.length; i++) {
BufferedImage img = new BufferedImage((int)Math.ceil(pgsize.width*zoom), (int)Math.ceil(pgsize.height*zoom), BufferedImage.TYPE_INT_RGB);
Graphics2D graphics = img.createGraphics();
graphics.setTransform(at);
graphics.setPaint(Color.white);
graphics.fill(new Rectangle2D.Float(0, 0, pgsize.width, pgsize.height));
slide[i].draw(graphics);
FileOutputStream out = new FileOutputStream("slide-" + (i + 1) + ".png");
javax.imageio.ImageIO.write(img, "png", out);
out.close();
}
}
}

Answering my own question, I subscribed to the development mailing list and asked this question.
The answer is that this functionailty is currently not supported by apache poi

There's an example class PPTX2PNG now bundled with POI that seems to work with decent results for the PPTX decks I've thrown at it:
http://svn.apache.org/repos/asf/poi/trunk/src/ooxml/java/org/apache/poi/xslf/util/PPTX2PNG.java

pptx4j can help you to create SVG in HTML (though there is still work to do to support all shapes); and then you could use one of the tools which create a image from an automated browser window.