Color tracking
import processing.video.*;
// Variable for capture device
Capture video;
// A variable for the color we are searching for.
color trackColor;
float centerX = 320;
float centerY = 240;
int diameter = 50;
int closestX;
int closestY;
void setup() {
size(640,480);
video = new Capture(this,width,height,15);
video.start();
// Start off tracking for red
trackColor = color(255,0,0);
smooth();
}
void draw() {
// Capture and display the video
if (video.available()) {
video.read();
}
video.loadPixels();
image(video,0,0);
// 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.
float worldRecord = 500;
// XY coordinate of closest color
closestX = 0;
closestY = 0;
// Begin loop to walk through every pixel
for (int x = 0; x < video.width; x ++ ) {
for (int y = 0; y < video.height; y ++ ) {
int loc = x + y*video.width;
// What is current color
color currentColor = video.pixels[loc];
float r1 = red(currentColor);
float g1 = green(currentColor);
float b1 = blue(currentColor);
float r2 = red(trackColor);
float g2 = green(trackColor);
float b2 = blue(trackColor);
// Using euclidean distance to compare colors
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.
// If current color is more similar to tracked color than
// closest color, save current location and current difference
if (d < worldRecord) {
worldRecord = d;
closestX = x;
closestY = y;
}
}
}
// We only consider the color found if its color distance is less than 10.
// This threshold of 200 is arbitrary and you can adjust this number depending on how accurate you require the tracking to be.
if (worldRecord < 150) {
// Draw a circle at the tracked pixel
fill(trackColor);
noStroke();
ellipse(closestX,closestY,20,20);
}
if ( isColorInCircle(centerX, centerY, diameter)) {
fill(0,255,0);
centerX = centerX + 1;
} else {
fill(0,0,255);
}
ellipse(centerX, centerY, diameter,diameter);
}
void mousePressed() {
// Save color where the mouse is clicked in trackColor variable
int loc = mouseX + mouseY*video.width;
trackColor = video.pixels[loc];
}
boolean isColorInCircle(float x, float y, int diameter) {
float distance = dist(x, y, closestX, closestY);
float radius = diameter / 2.0;
if ( distance < radius) {
return true;
} else {
return false;
}
}