Processing Forum

OpenGL and processing.video

[3 Replies]
- 03-Oct-2011 10:32 AM
- Forum: Core Library Questions
Hello!

I am trying to run a motion detection script using the default processing video library. The problem is that when I use the OpenGL renderer, the screen turns white and the code does not work anymore.

I really need to use OpenGL, since my program needs a fast renderer.

Does anyone know a way to make the two libraries work together?

Below is my isolated code for motion detection (it works fine without OpenGL):
1. import processing.opengl.*;
2. import processing.video.*;
3. // Variable for capture device
4. Capture video;
5. // Previous Frame
6. PImage prevFrame;
7. // How different must a pixel be to be a "motion" pixel
8. float threshold = 50;
10. // Count motion pixels to detect motion
11. HashMap pixeisEmMovimento = new HashMap();
12. boolean motionDetected = false;
13. int contagemMovimento;
15. void setup() {
16. size(320,240, OPENGL);
17. video = new Capture(this, width, height, 30);
18. // Create an empty image the same size as the video
19. prevFrame = createImage(video.width,video.height,RGB);
20. }
22. void draw() {
24. // Capture video
25. if (video.available()) {
26. // Save previous frame for motion detection!!
27. prevFrame.copy(video,0,0,video.width,video.height,0,0,video.width,video.height); // Before we read the new frame, we always save the previous frame for comparison!
28. prevFrame.updatePixels();
29. video.read();
30. }
32. loadPixels();
33. video.loadPixels();
34. prevFrame.loadPixels();
36. // Begin loop to walk through every pixel
37. for (int x = 0; x < video.width; x ++ ) {
38. for (int y = 0; y < video.height; y ++ ) {
40. int loc = x + y*video.width; // Step 1, what is the 1D pixel location
41. color current = video.pixels[loc]; // Step 2, what is the current color
42. color previous = prevFrame.pixels[loc]; // Step 3, what is the previous color
44. // Step 4, compare colors (previous vs. current)
45. float r1 = red(current); float g1 = green(current); float b1 = blue(current);
46. float r2 = red(previous); float g2 = green(previous); float b2 = blue(previous);
47. float diff = dist(r1,g1,b1,r2,g2,b2);
49. // Step 5, How different are the colors?
50. // If the color at that pixel has changed, then there is motion at that pixel.
51. if (diff > threshold) {
52. // If motion, display black
53. pixels[loc] = color(0);
54. pixeisEmMovimento.put(loc, "coiso");
55. } else {
56. // If not, display white
57. pixels[loc] = color(255);
58. pixeisEmMovimento.remove(loc);
59. }
60. }
61. }
63. if(contagemMovimento < 15) {
64. contagemMovimento++;
65. } else {
66. if(pixeisEmMovimento.size() > 0) {
67. motionDetected = true;
68. } else {
69. motionDetected = false;
70. }
71. contagemMovimento = 0;
72. }
74. println(motionDetected);
75. }

ProXML and special characters

[0 Replies]
- 04-Jun-2011 02:24 AM
- Forum: Contributed Library Questions
Hello,

I am using proxml in order to import structured information from a xml file. It works fine, except for one thing: the special characters are converted to html entities: «'», to «'», for example. Is there any way that I can get the characters correctly from the xml file or unescape after they're imported?

My xmlEvent:
1. void xmlEvent(proxml.XMLElement element) {
  citacoesXML = element;
  
  // citacoesXML.printElementTree(" ");
  proxml.XMLElement citacaoXML;
  proxml.XMLElement quoteAuthor;
  proxml.XMLElement authorQuote;
  
  // Contar o numero de quotes
  int childrenCount = citacoesXML.countChildren();
  
  // Definir o tamanho das arrays de quotes e autor, as quais a classe "frase" vai aceder, de acordo
  // com o numero de quotes no xml
  quoteXML = new String[childrenCount];
  authorXML = new String[childrenCount];
  
  for(int i = 0; i < citacoesXML.countChildren(); i++) {
      citacaoXML = citacoesXML.getChild(i);
      quoteAuthor = citacaoXML.getChild(2);
      authorQuote = citacaoXML.getChild(0);
      quoteXML[i] = quoteAuthor.getChild(0).toString();
      authorXML[i] = authorQuote.getChild(0).toString();
  }
  }
The declaration of the xml is
1. <?xml version="1.0" encoding="UTF-9">
I would appreciate any help or tips!

Thank you!

Drawing in alpha channel

[3 Replies]
- 28-Nov-2010 07:54 AM
- Forum: Programming Questions
Hello,

I am trying to achieve an image revealing effect with lines drawn by the user. To do this, I am placing a white square above the image to be revealed. What I would like to know is if it is possible to paint the alpha channel of this square in the space around the lines.

This would be better explained with an image:

I would appreciate any help!

Thank you

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