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Index › Programming Questions & Help › Video Capture,  Movie Playback,  Vision Libraries › Video Trails / Echo effect using blend mode
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Video Trails / Echo effect using blend mode (Read 1208 times)
kpimmel
Video Trails / Echo effect using blend mode
Jun 2nd, 2010, 11:03pm  
I'm working on a simple program to create trails for pre-visualizing light painting photography. The code works, but I find the image 'bleeds' toward to lower right of the frame - an undesired effect. Any ideas why this might be happening?

Thanks in advance
Kim


Code:

import processing.video.*;

Capture cam;
int[] maskArray;
static final int blendFactor = 255;
PImage previousFrame;
int capWidth = 640;
int capHeight = 480;


void setup() {
  size(capWidth, capHeight);
  frameRate(24);

  maskArray = new int[capWidth * capHeight];
  Arrays.fill(maskArray, blendFactor);
  cam = new Capture(this, capWidth, capHeight);
}


void draw() {
 
   previousFrame = get();
    previousFrame.mask(maskArray);
      
    cam.read();
    image(cam, 0, 0, 640, 480);
    
     blend(previousFrame, 0, 0, capWidth, capHeight, 0, 0, capWidth, capHeight, LIGHTEST);
}



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kpimmel
Re: Video Trails / Echo effect using blend mode
Reply #1 - Jun 3rd, 2010, 10:03pm  
Someone figured out the problem - seems to be a bug in the blend method (Thanks Josh!)

Code:
blend(previousFrame, 0, 0, capWidth-1, capHeight-1, 0, 0, capWidth-1, capHeight-1, LIGHTEST);
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