Processing Forum

How to calculate the density of certain color in an image?

[9 Replies]
- 12-Jan-2013 07:50 AM
- Forum: General Discussion
I would like to calculate the density of certain color in an image,
for example, the density of red color and get the center gravity where the x,y coordinate is.

How to do that? Is there certain function in processing to do that?

This code can not do motion detection, why?

[0 Replies]
- 01-Jan-2013 12:36 AM
- Forum: Contributed Library Questions
This is the original code that I plan to modify, anw this code works well to detect any motion, this code use common webcam attach to my computer, and I take it from here: http://www.learningprocessing.com/examples/chapter-16/example-16-13/
here is the code, that works:
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;
9. void setup() {
10. size(320,240);
11. video = new Capture(this, width, height, 30);
12. // Create an empty image the same size as the video
13. prevFrame = createImage(video.width,video.height,RGB);
14. }
15. void draw() {
16. // Capture video
17. if (video.available()) {
19. // Save previous frame for motion detection!!
20. prevFrame.copy(video,0,0,video.width,video.height,0,0,video.width,video.height);
21. prevFrame.updatePixels();
22. video.read();
23. }
24. loadPixels();
25. video.loadPixels();
26. prevFrame.loadPixels();
28. // Begin loop to walk through every pixel
29. for (int x = 0; x < video.width; x++ ) {
30. for (int y = 0; y < video.height; y++ ) {
31. int loc = x + y*video.width; // Step 1, what is the 1D pixel location
32. color current = video.pixels[loc]; // Step 2, what is the current color
33. color previous = prevFrame.pixels[loc]; // Step 3, what is the previous color
34. // Step 4, compare colors (previous vs. current)
35. float r1 = red(current); float g1 = green(current); float b1 = blue(current);
36. float r2 = red(previous); float g2 = green(previous); float b2 = blue(previous);
37. float diff = dist(r1,g1,b1,r2,g2,b2);
38. // Step 5, How different are the colors?
39. if (diff > threshold) {
40. // If motion, display black
41. pixels[loc] = color(0);
42. } else {
43. // If not, display white
44. pixels[loc] = color(255);
45. }
46. }
47. }
48. updatePixels();
49. }
After I modify it, because I would like to do motion detection not using webcam but using my kinect camera, so I modify like this:
2. import SimpleOpenNI.*;
3. SimpleOpenNI kinect;
5. // Previous Frame
6. PImage currentFrame;
7. PImage prevFrame;
10. // How different must a pixel be to be a "motion" pixel
11. float threshold =50;
14. void setup()
15. {
16. size(640,480);
17. kinect = new SimpleOpenNI (this);
19. kinect.enableRGB ();
21. // Create an empty image the same size as the currentFrame
22. prevFrame = createImage(640,480,RGB);
24. }
26. void draw()
27. {
28. kinect.update();
29. currentFrame = kinect.rgbImage ();
31. if (kinect.enableRGB() == true ){
34. prevFrame.copy (currentFrame,0,0, 640,480,0,0,640,480);
35. prevFrame.updatePixels();
36. image (currentFrame,0,0);
37. }
38. loadPixels();
39. currentFrame.loadPixels ();
40. prevFrame.loadPixels ();
43. // Begin loop to walk through every pixel
44. for (int x = 0; x < currentFrame.width; x++ ) {
45. for (int y = 0; y < currentFrame.height; y++ ) {
46. int loc = x + y*currentFrame.width; // Step 1, what is the 1D pixel location
47. color current = currentFrame.pixels[loc]; // Step 2, what is the current color
48. color previous = prevFrame.pixels[loc]; // Step 3, what is the previous color
49. // Step 4, compare colors (previous vs. current)
50. float r1 = red(current); float g1 = green(current); float b1 = blue(current);
51. float r2 = red(previous); float g2 = green(previous); float b2 = blue(previous);
52. float diff = dist(r1,g1,b1,r2,g2,b2);
53. // Step 5, How different are the colors?
54. if (diff > threshold) {
55. // If motion, display black
56. pixels[loc] = color(0);
57. } else {
58. // If not, display white
59. pixels[loc] = color(255);
60. }
61. }
62. }
63. updatePixels();
64. }
But it result on white screen window.

It seems dont work well.

Anyone could help me to fix this problem ? thank you!!

Can not track any clicked color ?

[2 Replies]
- 29-Dec-2012 10:04 AM
- Forum: Contributed Library Questions
This code I get from http://www.learningprocessing.com/examples/chapter-16/example-16-11/, and it works to activate my webcam then track anycolor that I click, here is the image:

Here is the code:
2. // Learning Processing
3. // Daniel Shiffman
4. // http://www.learningprocessing.com
6. // Example 16-11: Simple color tracking
8. import processing.video.*;
10. // Variable for capture device
11. Capture video;
13. // A variable for the color we are searching for.
14. color trackColor;
16. void setup() {
17. size(320,240);
18. video = new Capture(this,width,height,15);
19. // Start off tracking for red
20. trackColor = color(255,0,0);
21. smooth();
22. }
24. void draw() {
25. // Capture and display the video
26. if (video.available()) {
27. video.read();
28. }
29. video.loadPixels();
30. image(video,0,0);
32. // Before we begin searching, the "world record" for closest color is set to a high number that is easy for the first pixel to beat.
33. float worldRecord = 500;
35. // XY coordinate of closest color
36. int closestX = 0;
37. int closestY = 0;
39. // Begin loop to walk through every pixel
40. for (int x = 0; x < video.width; x ++ ) {
41. for (int y = 0; y < video.height; y ++ ) {
42. int loc = x + y*video.width;
43. // What is current color
44. color currentColor = video.pixels[loc];
45. float r1 = red(currentColor);
46. float g1 = green(currentColor);
47. float b1 = blue(currentColor);
48. float r2 = red(trackColor);
49. float g2 = green(trackColor);
50. float b2 = blue(trackColor);
52. // Using euclidean distance to compare colors
53. float d = dist(r1,g1,b1,r2,g2,b2); // We are using the dist( ) function to compare the current color with the color we are tracking.
55. // If current color is more similar to tracked color than
56. // closest color, save current location and current difference
57. if (d < worldRecord) {
58. worldRecord = d;
59. closestX = x;
60. closestY = y;
61. }
62. }
63. }
65. // We only consider the color found if its color distance is less than 10.
66. // This threshold of 10 is arbitrary and you can adjust this number depending on how accurate you require the tracking to be.
67. if (worldRecord < 10) {
68. // Draw a circle at the tracked pixel
69. fill(trackColor);
70. strokeWeight(4.0);
71. stroke(0);
72. ellipse(closestX,closestY,16,16);
73. }
74. }
76. void mousePressed() {
77. color c = get(mouseX, mouseY);
78. println("r: " + red(c) + " g: " + green(c) + " b: " + blue(c));
82. // Save color where the mouse is clicked in trackColor variable
83. int loc = mouseX + mouseY*video.width;
84. trackColor = video.pixels[loc];
85. }
After I modify it, It success to display image/video from Kinect, like this:
But it can not track any color if I click the mouse.

Here is the code modification:
2. import SimpleOpenNI.*;
3. SimpleOpenNI kinect;
4. color trackColor;
6. // Frame
7. PImage currentFrame;
10. void setup()
11. {
12. size(640, 480);
13. kinect = new SimpleOpenNI(this);
16. kinect.enableRGB();
18. trackColor = color (255,0,0);
19. smooth ();
21. currentFrame = createImage (640,480, RGB);
22. }
24. void draw()
25. {
26. kinect.update();
27. currentFrame.loadPixels();
28. PImage depthImage = kinect.depthImage();
29. PImage currentFrame = kinect.rgbImage ();
30. image(currentFrame,0,0);
33. // Before we begin searching, the "world record" for closest color is set to a high number that is easy for the first pixel to beat.
34. float worldRecord = 500;
36. // XY coordinate of closest color
37. int closestX = 0;
38. int closestY = 0;
40. // Begin loop to walk through every pixel
41. for (int x = 0; x < currentFrame.width; x ++ ) {
42. for (int y = 0; y < currentFrame.height; y ++ ) {
43. int loc = x + y*currentFrame.width;
44. // What is current color
45. color currentColor = currentFrame.pixels[loc];
46. float r1 = red(currentColor);
47. float g1 = green(currentColor);
48. float b1 = blue(currentColor);
49. float r2 = red(trackColor);
50. float g2 = green(trackColor);
51. float b2 = blue(trackColor);
53. // Using euclidean distance to compare colors
54. float d = dist(r1,g1,b1,r2,g2,b2); // We are using the dist( ) function to compare the current color with the color we are tracking.
56. // If current color is more similar to tracked color than
57. // closest color, save current location and current difference
58. if (d < worldRecord) {
59. worldRecord = d;
60. closestX = x;
61. closestY = y;
62. }
63. }
64. }
66. // We only consider the color found if its color distance is less than 10.
67. // This threshold of 10 is arbitrary and you can adjust this number depending on how accurate you require the tracking to be.
68. if (worldRecord < 10) {
69. // Draw a circle at the tracked pixel
70. fill(trackColor);
71. strokeWeight(4.0);
72. stroke(0);
73. ellipse(closestX,closestY,16,16);
74. }
77. }
80. void mousePressed(){
81. color c = get(mouseX, mouseY);
82. println("r: " + red(c) + " g: " + green(c) + " b: " + blue(c));
84. // Save color where the mouse is clicked in trackColor variable
85. int loc = mouseX + mouseY*currentFrame.width;
86. println(loc);
88. trackColor = currentFrame.pixels[loc];
89. }
Anyone can help me to find which code I make error so it can not track any color?

I really need to track color but using Kinect cam and processing not webcam.

Thank you very much.

PImage to display video?

[5 Replies]
- 29-Dec-2012 01:48 AM
- Forum: Contributed Library Questions
This is the code I modify to display depthImage, rgbImage, and the copy of rgbImage
2. import SimpleOpenNI.*;
3. SimpleOpenNI kinect;
4. color trackColor;
6. // Frame
7. PImage currentFrame;
8. PImage rgbImage;
10. void setup()
11. {
12. size(640*3, 480);
13. kinect = new SimpleOpenNI(this);
15. kinect.enableDepth();
16. kinect.enableRGB();
18. trackColor = color (255,0,0);
19. smooth ();
21. currentFrame = createImage (640,480, RGB);
22. }
24. void draw()
25. {
26. kinect.update();
28. PImage depthImage = kinect.depthImage();
29. PImage rgbImage = kinect.rgbImage();
31. image(depthImage, 0, 0);
32. image(rgbImage, 640, 0);
33. currentFrame.copy(kinect.rgbImage(),640,0,640,480,1280,0,640,480);
34. currentFrame.updatePixels();
35. loadPixels();
36. currentFrame.loadPixels();
37. image(currentFrame,1280,0);
39. }
41. void mousePressed(){
42. color c = get(mouseX, mouseY);
43. println("r: " + red(c) + " g: " + green(c) + " b: " + blue(c));
45. // Save color where the mouse is clicked in trackColor variable
46. int loc = mouseX + mouseY*width;
47. println(loc);
48. }
It shows this:
the code works for 1st and 2nd frame (which is DepthImage and RGBImage),

But I wonder why it display black at the 3rd Frame? Because I expect it display the copy of the 2nd frane (which is RGBImage).

Is there any wrong in my code?

I am using PImage to display video bcause I would like to use some of PImage methods (like pixels) which inspired from this simple motion detection code and single color tracking code:

http://www.learningprocessing.com/examples/chapter-16/example-16-11/

http://www.learningprocessing.com/examples/chapter-16/example-16-13/

The core of my modification is, I would like to track color but not using webcam, but using kinect cam.

Any reply or question for clarity, do not hesitate to ask.

Can not run Blobs samples from OpenCV in processing 1.5.1

[1 Reply]
- 21-Dec-2012 06:07 AM
- Forum: Contributed Library Questions
Here below is the code of the blob samples:
2. import hypermedia.video.*;
6. OpenCV opencv;
8. int w = 320;
9. int h = 240;
10. int threshold = 80;
12. boolean find=true;
14. PFont font;
16. void setup() {
18. size( w*2+30, h*2+30 );
20. opencv = new OpenCV( this );
21. opencv.capture(w,h);
23. font = loadFont( "AndaleMono.vlw" );
24. textFont( font );
26. println( "Drag mouse inside sketch window to change threshold" );
27. println( "Press space bar to record background image" );
29. }
33. void draw() {
35. background(0);
36. opencv.read();
37. //opencv.flip( OpenCV.FLIP_HORIZONTAL );
39. image( opencv.image(), 10, 10 ); // RGB image
40. image( opencv.image(OpenCV.GRAY), 20+w, 10 ); // GRAY image
41. image( opencv.image(OpenCV.MEMORY), 10, 20+h ); // image in memory
43. opencv.absDiff();
44. opencv.threshold(threshold);
45. image( opencv.image(OpenCV.GRAY), 20+w, 20+h ); // absolute difference image
48. // working with blobs
49. Blob[] blobs = opencv.blobs( 100, w*h/3, 20, true );
51. noFill();
53. pushMatrix();
54. translate(20+w,20+h);
56. for( int i=0; i<blobs.length; i++ ) {
58. Rectangle bounding_rect = blobs[i].rectangle;
59. float area = blobs[i].area;
60. float circumference = blobs[i].length;
61. Point centroid = blobs[i].centroid;
62. Point[] points = blobs[i].points;
64. // rectangle
65. noFill();
66. stroke( blobs[i].isHole ? 128 : 64 );
67. rect( bounding_rect.x, bounding_rect.y, bounding_rect.width, bounding_rect.height );
70. // centroid
71. stroke(0,0,255);
72. line( centroid.x-5, centroid.y, centroid.x+5, centroid.y );
73. line( centroid.x, centroid.y-5, centroid.x, centroid.y+5 );
74. noStroke();
75. fill(0,0,255);
76. text( area,centroid.x+5, centroid.y+5 );
79. fill(255,0,255,64);
80. stroke(255,0,255);
81. if ( points.length>0 ) {
82. beginShape();
83. for( int j=0; j<points.length; j++ ) {
84. vertex( points[j].x, points[j].y );
85. }
86. endShape(CLOSE);
87. }
89. noStroke();
90. fill(255,0,255);
91. text( circumference, centroid.x+5, centroid.y+15 );
93. }
94. popMatrix();
96. }
98. void keyPressed() {
99. if ( key==' ' ) opencv.remember();
100. }
102. void mouseDragged() {
103. threshold = int( map(mouseX,0,width,0,255) );
104. }
106. public void stop() {
107. opencv.stop();
108. super.stop();
109. }
But when I run it, it shows error like this:

Cannot find a class or type named "Rectangle"

Anyone knows how to fix it?

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