allright, taking the pricture program works. He puts the pictures in the 'pool'

I'm guess something goed wrong with the path. and I tried to put 'path' on the place of the path where it is right now.

But in the slideshow I added the code and I get an null pointer exception on this highlighted line:

Code:

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]);
  }
 }
} 

If I add the line it should look like this right?

Code:

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

It now says ' cannot find anything named 'folder'' And he probably also doesn;t find imgFilter. Do I need to set something up in the global?

All right, tuning into the discussion again

I wrote the programs on two different computers, cause I only have a webcam on my EEE, so I had not tested it as a combination. I have tried copying full images into the directory while the slideshow program was running though and this worked without problem.

Like PhiLho said before, I think the current problem with half images etc. is that the image is still being saved by one program (webcamsnaps) while the other starts loading it (slideshow). In addition to the temporary rename suggestion I see two other possible solutions:

1. Delay the time between seeing/loading the filename and loading the actual file. This in order to give the webcamsnaps program more time to fully save the file.

2. Integrate both programs into one program. Two individual programs is great for two computers. And btw this started as two different threads. But you said somewhere that you're now running both on the same computer. So integrating the two might be a better idea and also prevent problems like this.

So those are ideas. With regard to implementation. As you might have guessed from my absence, I'm short on time. Both due to work and personal projects. So I don't know when I will have time to take a closer look at this.

He Amnon,

It's a shame (but I understand) that you don't have the time to take a look. It needs to be finished before sunday :S. And just a few small things need to be done.

I hope philho wakes up soon. It's almost there!!!

Thanks so far for all your help!

Note: my guard line was intended to be at the start of display()...
But it was a good idea to give the current state of the code, I saw I made a stupid loadPhotos() function...

Since you got code that doesn't rely actually on webcam, I could test it just by adding images to the watched dir. I made a number of small changes:
Code:

import processing.opengl.*;

ArrayList photos = new ArrayList();
String[] fileNameList;
PImage[] loadedPhotos;
int counter, fileCount, imageCount;
boolean autoPlay = true; // by default autoplay is OFF
HashSet loadedFileNames = new HashSet();
String path = "/Users/menno/Documents/Processing/picture_pool/";

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

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

void loadFileNames() {
  File folder = new File(path);
  FilenameFilter imgFilter = new FilenameFilter() {
    public boolean accept(File dir, String name) {
	return !name.startsWith("_") &&
	    (name.toLowerCase().endsWith(".jpg") ||
	    name.toLowerCase().endsWith(".png"));
    } 
  };
  fileNameList = folder.list(imgFilter);
} 

void loadPhotos() {
  for (int i = 0; i < fileNameList.length; i++) {
    if (!loadedFileNames.contains(fileNameList[i])) {
	// A new file!
	loadedPhotos[imageCount++] = loadImage(path + fileNameList[i]);
	loadedFileNames.add(fileNameList[i]);
    }
  }
}

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


void autoPlay() {
  counter++;
  if (counter >= 60 && photos.size() < imageCount) 
  {
    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() < imageCount) {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;
  boolean bStopped;

  Photo(float targetXposTemp, float targetYposTemp, float rotationTemp) {
    photo = loadedPhotos[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 (bStopped) return;
    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;
    } else {
	bStopped = true;
    }
  }
} 

Seems to work OK for my limited testing.

Here I'm AGIAN with a question!

Yesterday I tested it on my mac book pro and it seemed to work fine with memory etc. But now I've tested the whole installation on an Imac (white with 2GB memory) and it seems that it runs out of memory after a while (20 pics) and crashes . I increased the memory in the prefrences (didn't help)
Is there a way to clear the memory after every run?

And this line not seems to work. I tried to put it to 20 but whem he reaches the 20 slides (pics) it stops and gifs an out of bounce error.

I didn't changed the loadedPhotos size!! I've an idea but don't know if it will work.

idea:
If I make a new folder on the computer. and than tell the slideshow script, when the photoCount is 20 move all pictures to the new folder.