Changing webcam-pixels to "nearest" color from color palette array

Processing Libraries
7

so you want change the colors of the picture?

if you want quantify the color there must be a rule like
color name x = color(hx,sx,bx) range:

  • hue from a to hx to b,
  • saturation from c to sx to d,
  • brightness from e to bx to f,

do you have that rule or math?

and that calc you need to do on each pix color?

import processing.video.*;
Capture video;

void setup() {
  size(320, 240);
  colorMode(HSB);
  video = new Capture(this, width, height);
  video.start();
}

void draw() { 
  if (video.available()) {
    video.read();
    //video.filter(POSTERIZE, 4);
    //image(video, 0, 0);                 // show org or filtered picture
    video.loadPixels();
    int count = video.width * video.height;
    for (int i = 0; i < count; i++) {
      color c = video.pixels[i];
      float h = hue(c);
      float s = saturation(c);
      float b = brightness(c);
      if ( hprint ) println("i "+i+" h "+nf(h, 0, 1)+" s "+nf(s, 0, 1)+" b "+nf(b, 0, 1) );
      // what is the RULE for a correct color?
      video.pixels[i] = color(h, s, b);
    }
    updatePixels();
    hprint = false;

    image(video, 0, 0);                   // show mod picture
  }
}

boolean hprint = false;
void keyPressed() {
  if ( key == 'h' ) hprint = true;
}

a example for ranging math here with WEB SAFE COLORS

// https://processing.org/reference/filter_.html
// https://discourse.processing.org/t/changing-webcam-pixels-to-nearest-color-from-color-palette-array/14811

import processing.video.*;
Capture video;

void setup() {
  size(160, 120);
  //colorMode(HSB,100);    // as we later change float to int this here is already POSTERIZE ( reduced color resolution )
  video = new Capture(this, width, height);
  video.start();
}

void draw() { 
  if (video.available()) {
    video.read();
    //video.filter(POSTERIZE, 4);         
    //image(video, 0, 0);                 // show org or filtered picture
    video.loadPixels();
    int count = video.width * video.height;
    for (int i = 0; i < count; i++) {
      color c = video.pixels[i];
      int h  = (int)hue(c);
      int s  = (int)saturation(c);
      int br = (int)brightness(c);
      int r  = (int)red(c);
      int g  = (int)green(c);
      int bl = (int)blue(c);
      // what is the RULE for a correct color?
      //h = h;
      //s = s;
      //br = br;
      // test web safe quantification
      int wr  = websafe(r);
      int wg  = websafe(g);
      int wbl = websafe(bl);
      if ( hsbprint ) println("i "+i+" h "+h+" s "+s+" b "+br+" / r "+r+" g "+g+" b "+bl+" // websafe wr "+wr+" wg "+wg+" wbl "+wbl);
      video.pixels[i] = color(wr, wg, wbl); //color(h, s, b);
    }
    updatePixels();
    hsbprint = false;

    image(video, 0, 0);                   // show mod picture
  }
}

int websafe(int c) {
  //https://www.rapidtables.com/web/color/Web_Safe.html
  // c from 0 ..255 for r g bl / w in 6 steps for 255 step color space
  int w = 0;
  if       ( c < 25 ) w = 0;
  else if  ( c < 75 ) w = 51;
  else if  ( c <125 ) w = 102;
  else if  ( c <175 ) w = 153;
  else if  ( c <225 ) w = 204;
  else                w = 255;
  return w;
}



boolean hsbprint = false;
void keyPressed() {
  if ( key == 'h' ) hsbprint = true;
}