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problem in fire effect with webcam motion detection

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- 01-May-2013 04:44 PM
- Forum: Core Library Questions
I am using the sketch below, which creates a fire effect on motion detection when using a webcam. The problem is, I am trying to be able to see the live feed instead of black image and background. I keep changing parameters but with no success. Any thoughts?
2. import processing.video.*;
4. int numPixels;
5. int threshold = 50;
6. int[] currentPixels;
7. int[] lastGoodPixels;
8. int[] backgroundPixels;
9. Capture video;
10. PImage pg;
12. int effectWidth;
13. int effectHeight;
15. // This will contain the pixels used to calculate the fire effect
16. int[][] fire;
17. // Flame colors
18. color[] palette;
19. int[] calc1,calc2,calc3,calc4,calc5;
22. void setup()
23. {
24. // Change size to 320 x 240 if too slow at 640 x 480
25. size(640, 480, JAVA2D);
26. //size(320, 240, JAVA2D);
28. effectWidth = width/2;
29. effectHeight = height/2;
30. pg = createImage(effectWidth, effectHeight, RGB);
32. video = new Capture(this, effectWidth, effectHeight, 30);
34. frameRate(60);
35. numPixels = effectWidth * effectHeight;
37. // Create arrays to store the current and background image
38. backgroundPixels = new int[numPixels];
39. currentPixels = new int[numPixels];
40. lastGoodPixels = new int[numPixels];
42. calc1 = new int[effectWidth];
43. calc3 = new int[effectWidth];
44. calc4 = new int[effectWidth];
45. calc2 = new int[effectHeight];
46. calc5 = new int[effectHeight];
48. colorMode(HSB);
50. fire = new int[effectWidth][effectHeight];
51. palette = new color[255];
53. // Generate the palette
54. for(int x = 0; x < palette.length; x++) {
55. //Hue goes from 0 to 85: red to yellow
56. //Saturation is always the maximum: 255
57. //Lightness is 0..255 for x=0..128, and 255 for x=128..255
58. palette[x] = color(x/3, 255, constrain(x*3, 0, 255));
59. }
61. // Precalculate which pixel values to add during animation loop
62. for (int x = 0; x < effectWidth; x++) {
63. calc1[x] = x % effectWidth;
64. calc3[x] = (x - 1 + effectWidth) % effectWidth;
65. calc4[x] = (x + 1) % effectWidth;
66. }
68. for(int y = 0; y < effectHeight; y++) {
69. calc2[y] = (y + 1) % effectHeight;
70. calc5[y] = (y + 2) % effectHeight;
71. }
72. video.start();
73. }
77. void captureEvent(Capture which)
78. {
79. if (which!=video || !video.available())
80. return;
82. video.read(); // Read a new video frame
83. video.loadPixels(); // Make the pixels of video available
85. // Difference between the current frame and the stored background
86. int presenceSum = 0;
88. // For each pixel in the video frame...
89. for (int i = 0; i < numPixels; i++)
90. {
91. // Fetch the current color in that location, and also the color
92. // of the background in that spot
93. color currColor = video.pixels[i] & 0xFF;
94. color bkgdColor = backgroundPixels[i] & 0xFF;
95. int diff = abs(currColor - bkgdColor);
96. currentPixels[i] = diff;
97. presenceSum += diff;
98. }
99. if (presenceSum > 0)
100. {
101. // image changed
102. arraycopy(video.pixels, backgroundPixels);
103. arraycopy(currentPixels, lastGoodPixels);
104. println("update " + presenceSum);
105. }
106. }
109. void draw()
110. {
111. pg.loadPixels();
113. int counter = 0;
114. // Do the fire calculations for every pixel, from top to bottom
115. for (int y = 0; y < effectHeight; y++)
116. {
117. for(int x = 0; x < effectWidth; x++)
118. {
119. int pixel = lastGoodPixels[counter];
120. if (pixel > threshold)
121. {
122. pixel = min((pixel - threshold)/2 + fire[x][y], 128);
123. fire[x][y] = pixel;
124. }
125. else
126. {
127. // Add pixel values around current pixel
128. fire[x][y] =
129. ((fire[calc3[x]][calc2[y]]
130. + fire[calc1[x]][calc2[y]]
131. + fire[calc4[x]][calc2[y]]
132. + fire[calc1[x]][calc5[y]]) << 5) / 129;
133. }
134. // Output everything to screen using our palette colors
135. pg.pixels[counter++] = palette[fire[x][y]];
136. }
137. }
138. pg.updatePixels();
140. // display the results
141. image(pg,0,0,width,height);
143. println("drawn");
144. }

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