The problem might be in the line:
for (int i = fileCount; i < loadFilenames.length; i++)
I can be wrong, but I think Java offers no guarantee on the order of the list of files. It can be alphabetical, chronological, random... Might even depend on the underlying system.
It is more reliable to put the file names (or paths) in a HashSet: it allows to quickly check if a name is already loaded (if it is already in the HashSet).

Side note: You don't have to use dataPath with an absolute path (it just returns this path...).

oh cheered to quickly :S I'm going to have a look at your answer philho!

Do you know where I can find something about a hashset?

Hello,

I got a very good response (help) on my previous posts so I thought I'll try it again.
I've two programs running at the same time. One is taking a picture when a face is recognized and saves the files to a folder. The other one is playing a slideshow and checks if new pictures are been made by the other program. The program which takes the photo's works properly accept the follow error once in a while.
sun.awt.image.PNGImageDecoder$PNGException: bogus length: -1
     at sun.awt.image.PNGImageDecoder.getChunk(PNGImageDecoder.java:661)
     at sun.awt.image.PNGImageDecoder.getData(PNGImageDecoder.java:674)
     at sun.awt.image.PNGImageDecoder.produceImage(PNGImageDecoder.java:221)
     at sun.awt.image.InputStreamImageSource.doFetch(InputStreamImageSource.java:246)
     at sun.awt.image.ImageFetcher.fetchloop(ImageFetcher.java:172)
     at sun.awt.image.ImageFetcher.run(ImageFetcher.java:136)
The file /Users/menno/Documents/Processing/taking_pics/faces2010-6-9 12.25.6.png contains bad image data, or may not be an image.
sun.awt.image.PNGImageDecoder$PNGException: bogus length: -1
     at sun.awt.image.PNGImageDecoder.getChunk(PNGImageDecoder.java:661)
     at sun.awt.image.PNGImageDecoder.getData(PNGImageDecoder.java:674)
     at sun.awt.image.PNGImageDecoder.produceImage(PNGImageDecoder.java:221)
     at sun.awt.image.InputStreamImageSource.doFetch(InputStreamImageSource.java:246)
     at sun.awt.image.ImageFetcher.fetchloop(ImageFetcher.java:172)
     at sun.awt.image.ImageFetcher.run(ImageFetcher.java:136)

The other program (the slideshow) don't work properly. If I start the program he read out the pictures from a folder. If there are 5 pictures in the folder he reads them out properly. When I start the 'taking pictures' program an it start making new pictures the slideshow recognizes new pictures but don't display them correctly. Or he loades the photos in for a small part or not at all.
When I restart the 'slideshow' program he does read the new photos correctly.

Anyone ideas?

Here's the code from the slideshow (rewritten by amnon) If some want to have a look at the 'taking pictures' program let me know.

Code:
//***************************************************************//
// Dynamic Image Slideshow
// by amnonP5 <http://amnonp5.wordpress.com>
//
// space = Add slide
//     z = Turn ON / OFF the autoplay function
//     x = Delete last slide
//     c = Clear all slides
//
// Comment IN / OUT: print added image message to console
// Comment IN / OUT: auto-reset slideshow at last slide
//
//***************************************************************//

import processing.opengl.*;

ArrayList photos = new ArrayList();
String[] loadFilenames;
PImage[] loadPhotos;
int counter, fileCount;
boolean autoPlay = true; // by default autoplay is OFF

void setup() {
 size(1280,720,OPENGL);
//  size(screen.width,screen.height,OPENGL); // full screen mode
 smooth();
 loadPhotos = new PImage[100]; // maximum of 10.000 images
 loadFilenames();
 loadPhotos(); // all existing images are loaded in setup
 fileCount = loadFilenames.length;
}

void draw() {
 background(51);
 checkNew(); // checks for new images in the data directory every draw cycle
 if(autoPlay) {autoPlay();}
 for (int i = 0; i < photos.size(); i++) {
   Photo s = (Photo) photos.get(i);
   s.display();
   s.move();
   
 }
if (photos.size() == fileCount) {photos.clear(); loadPhotos();} // reset slideshow when it reaches the last slide
}

void loadFilenames() {
 java.io.File folder = new java.io.File(dataPath("/Users/menno/Documents/Processing/taking_pics/")); // reads files from data folder
 java.io.FilenameFilter imgFilter = new java.io.FilenameFilter() {boolean accept(File dir, String name) {return name.toLowerCase().endsWith(".jpg") || name.toLowerCase().endsWith(".png");} };
 loadFilenames = folder.list(imgFilter);
}

void loadPhotos() {
 for (int i = fileCount; i < loadFilenames.length; i++) { // only load new images
   loadPhotos[i] = loadImage("/Users/menno/Documents/Processing/taking_pics/" + loadFilenames[i]);

// println("Photo added: " + loadFilenames[i]); // print added image message to console
 }
}

void checkNew() {
 loadFilenames();
 if (loadFilenames.length > fileCount) {loadPhotos(); fileCount = loadFilenames.length;} // only call loadPhotos if there are new images
}

void autoPlay() {
 counter++;
 if (counter >= 60 && photos.size() < loadFilenames.length) {photos.add(new Photo(random(80,width-80),random(60,height-60),random(-30,30))); counter=0;}
}

void keyPressed() {
 if (key == 'z') {if(autoPlay) {autoPlay = false;} else {autoPlay = true;}}
 if (key == ' ') {if (photos.size() < loadFilenames.length) {photos.add(new Photo(random(80,width-80),random(60,height-60),random(-30,30)));}}
 if (key == 'x') {if (photos.size() > 0) {photos.remove(photos.size()-1);}}
 if (key == 'c') {photos.clear();}
}

class Photo {
 PImage photo;
 float targetXpos;
 float targetYpos;
 float rotation;
 float xpos;
 float ypos;
 float easing;

 Photo(float targetXposTemp, float targetYposTemp, float rotationTemp) {
   photo = loadPhotos[photos.size()];
   xpos = width/2;
   ypos = -130;
   targetXpos = targetXposTemp;
   targetYpos = targetYposTemp;
   rotation = rotationTemp;
   easing = 0.1;
 }

 void display() {
   rectMode(CENTER);
   imageMode(CENTER);
   noStroke();

   pushMatrix();

   translate(width/2,height/2);
   rotate(radians(rotation));
   translate(-width/2,-height/2);

   translate(xpos,ypos);

   fill(0,0,0,50);
   rect(4,4,330,250);
   fill(255,255,255);
   rect(0,0,330,250);
   image(photo,0,0,320,240);

   popMatrix();
 }

 void move() {
   if (dist(xpos,ypos,targetXpos,targetYpos) > 1) { // only move if the destination has not been reached
   xpos = (1-easing) * xpos + (easing) * targetXpos;
   ypos = (1-easing) * ypos + (easing) * targetYpos;
   }
 }
}

arie willem wrote on Jun 9^th, 2010, 6:38am:

Bad idea, the answered topics are still useful to people searching the forum... Plus as you see you can delete only your own messages, not whole threads.
Thanks for restoring the original question.

What do you meen by:might need to reset with photos?

It still does the same and the slide show script shows the following errors. I uploaded a screenshot.

http://www.idablo.nl/werk/program.png

The weird thing is that he does make a complete picture in the folder but in the slideshow programs it shows half of the image.
And he does read (count) the number of images.

Maybe the following error tells you something.

java.awt.Frame[frame0,197,72,320x262,title=taking_pics,normal]

The file /Users/menno/Documents/Processing/taking_pics/faces2010-6-9 23.29.49.jpg contains bad image data, or may not be an image.

java.awt.Frame[frame0,197,72,320x262,title=taking_pics,normal]

Premature end of JPEG file
Premature end of JPEG file

java.awt.Frame[frame0,197,72,320x262,title=taking_pics,normal]
java.awt.Frame[frame0,197,72,320x262,title=taking_pics,normal]
java.awt.Frame[frame0,197,72,320x262,title=taking_pics,normal]

Premature end of JPEG file

java.awt.Frame[frame0,197,72,320x262,title=taking_pics,normal]

Premature end of JPEG file
Exception in thread "Animation Thread" java.lang.NullPointerException
     at processing.core.PGraphics.image(PGraphics.java:2197)
     at processing.core.PApplet.image(PApplet.java:7286)
     at slideshow$Photo.display(slideshow.java:134)
     at slideshow.draw(slideshow.java:58)
     at processing.core.PApplet.handleDraw(PApplet.java:1425)
     at processing.core.PApplet.run(PApplet.java:1327)
     at java.lang.Thread.run(Thread.java:613)

java.awt.Frame[frame0,197,72,320x262,title=taking_pics,normal]
java.awt.Frame[frame0,197,72,320x262,title=taking_pics,normal]
java.awt.Frame[frame0,197,72,320x262,title=taking_pics,normal]
java.awt.Frame[frame0,197,72,320x262,title=taking_pics,normal]

That sound like a solution. Did you see the screenshot at http://www.idablo.nl/werk/program.png

I'll try to write it to a temp file. do you know a good refrence?

Ok I tried to look up something and implement it in the code.

But when I fill in .jtemp as a filename it saving it as .....jtemp.tif

And if I change the oldname file extension to .jtemp.tif it doesn't do anything.
I guess you meant adding this code to the program which makes the pictures. And put it after making a picture.


Code:

  Rectangle[] faces = opencv.detect(1.2,2,OpenCV.HAAR_DO_CANNY_PRUNING,40,40);

  if (pictureJustTaken == false && faces.length >= 1) {
    saveFrame("faces" + year() + "-" + month() + "-"  + day() + " "  + hour() + "."  + minute() + "."  + second() + ".jtemp");
    pictureJustTaken = true;
    
    String oldname=dataPath("faces" + year() + "-" + month() + "-"  + day() + " "  + hour() + "."  + minute() + "."  + second() + ".jtemp.tif");
    File ff=new File(oldname);
    String newname=dataPath("faces" + year() + "-" + month() + "-"  + day() + " "  + hour() + "."  + minute() + "."  + second() + ".jpg");
    ff.renameTo(new File(newname));
    
    startTimer = millis();
    println(frame);
  } 

ok these are the two codes now. Do you think this should work?

The first one reads the images and shows it as a slideshow

Code:

//***************************************************************//
// Dynamic Image Slideshow
// by amnonP5 <http://amnonp5.wordpress.com>
// 
// space = Add slide
//     z = Turn ON / OFF the autoplay function
//     x = Delete last slide
//     c = Clear all slides
// 
// Comment IN / OUT: print added image message to console
// Comment IN / OUT: auto-reset slideshow at last slide
// 
//***************************************************************//

import processing.opengl.*;

ArrayList photos = new ArrayList();
String[] loadFilenames;
PImage[] loadPhotos;
int counter, fileCount;
boolean autoPlay = true; // by default autoplay is OFF
HashSet loadedFileNames = new HashSet();

void setup() {
  size(1024,768,OPENGL);
  //size(screen.width,screen.height,OPENGL); // full screen mode
  smooth();
  loadPhotos = new PImage[100]; // maximum of 10.000 images
  loadFilenames();
  loadPhotos(); // all existing images are loaded in setup
  fileCount = loadFilenames.length;
}

void draw() {
  background(51);
  checkNew(); // checks for new images in the data directory every draw cycle
  if(autoPlay) {autoPlay();}
  for (int i = 0; i < photos.size(); i++) {
    Photo s = (Photo) photos.get(i);
    s.display();
    s.move();
    
  }
 if (photos.size() == fileCount) {photos.clear(); loadPhotos();} // reset slideshow when it reaches the last slide
}

  void loadFilenames() {
  File folder = dataFile("/Users/menno/Documents/Processing/taking_pics/"); // reads files from data folder
  FilenameFilter imgFilter = new FilenameFilter() {
  boolean accept(File dir, String name) {
  return !name.startsWith(".tif") && (name.toLowerCase().endsWith(".png") || name.toLowerCase().endsWith(".png"));
  } 
  };
  loadFilenames = folder.list(imgFilter);
  } 

//void loadFilenames() {
//  java.io.File folder = new java.io.File(dataPath("/Users/menno/Documents/Processing/taking_pics2/")); // reads files from data folder
//  java.io.FilenameFilter imgFilter = new java.io.FilenameFilter() {boolean accept(File dir, String name) {return name.toLowerCase().endsWith(".png") || name.toLowerCase().endsWith(".png");} };
//  loadFilenames = folder.list(imgFilter);
  
//}

void loadPhotos() {
 for (int i = 0; i < loadFilenames.length; i++) {
  if (!loadedFileNames.contains(loadFilenames[i])) {
   loadPhotos[i] = loadImage("/Users/menno/Documents/Processing/taking_pics/" + loadFilenames[i]);
   loadedFileNames.add(loadFilenames[i]);
  }
 }
}

void checkNew() {
  loadFilenames();
  if (loadFilenames.length > fileCount) {loadPhotos(); fileCount = loadFilenames.length;} // only call loadPhotos if there are new images
}


void autoPlay() {
  counter++;
  if (counter >= 60 && photos.size() < loadFilenames.length) {photos.add(new Photo(random(80,width-80),random(60,height-60),random(-30,30))); counter=0;}
}

void keyPressed() {
  if (key == 'z') {if(autoPlay) {autoPlay = false;} else {autoPlay = true;}}
  if (key == ' ') {if (photos.size() < loadFilenames.length) {photos.add(new Photo(random(80,width-80),random(60,height-60),random(-30,30)));}}
  if (key == 'x') {if (photos.size() > 0) {photos.remove(photos.size()-1);}}
  if (key == 'c') {photos.clear();}
}

class Photo {
  PImage photo;
  float targetXpos;
  float targetYpos;
  float rotation;
  float xpos;
  float ypos;
  float easing;

  Photo(float targetXposTemp, float targetYposTemp, float rotationTemp) {
    photo = loadPhotos[photos.size()];
    xpos = width/2;
    ypos = -130;
    targetXpos = targetXposTemp;
    targetYpos = targetYposTemp;
    rotation = rotationTemp;
    easing = 0.1;
  }

  void display() {
    rectMode(CENTER);
    imageMode(CENTER);
    noStroke();

    pushMatrix();

    translate(width/2,height/2);
    rotate(radians(rotation));
    translate(-width/2,-height/2);

    translate(xpos,ypos);

    fill(0,0,0,50);
    rect(4,4,330,250);
    fill(255,255,255);
    rect(0,0,330,250);
    image(photo,0,0,320,240);

    popMatrix(); 
  }

  void move() {
    if (dist(xpos,ypos,targetXpos,targetYpos) > 1) { // only move if the destination has not been reached
    xpos = (1-easing) * xpos + (easing) * targetXpos;
    ypos = (1-easing) * ypos + (easing) * targetYpos;
    }
  }
}
  

And the second one is taking the images!

Code:

import hypermedia.video.*;
import java.awt.Rectangle;

OpenCV opencv;
boolean pictureJustTaken = false;
int startTimer;
int interval = 5; // interval in seconds

void setup() {
  size(320,240);
  opencv = new OpenCV(this);
  opencv.capture(width,height);
  opencv.cascade(OpenCV.CASCADE_FRONTALFACE_ALT);
}

void draw() {
  opencv.read();
  image(opencv.image(),0,0);

   Rectangle[] faces = opencv.detect(1.2,2,OpenCV.HAAR_DO_CANNY_PRUNING,40,40);

  if (pictureJustTaken == false && faces.length >= 1) {
    save("faces" + year() + "-" + month() + "-"  + day() + " "  + hour() + "."  + minute() + "."  + second() + ".jtemp");
    pictureJustTaken = true;
    
    String oldname=dataPath("/Users/menno/Documents/Processing/taking_pics/");
    File ff=new File(".tif");
    
    startTimer = millis();
    println(frame);
  } 

  if (pictureJustTaken) {
    if (millis() - startTimer > (interval * 1000)) {pictureJustTaken = false;}
  }
}

public void stop() {
  opencv.stop();
  super.stop();
}