spmacdonald's dice portrait

dice-portrait.py

# http://web.archive.org/web/20091015013516/http://www.elusivesnark.com/2008/11/carolines-dice-portrait.html

PImage img;
PImage cropped_img;
PImage patch;

int _width = 640;
int _height = 1024;
int patch_w = 16;
int patch_h = 16;
int pip_size = 4;

void setup() {
    size(_width, _height);
    img = loadImage("Caroline.jpg");
    img.resize(1536, 1024);
    cropped_img = img.get(250, 0, _width, _height);
}

// Draw quantized image
void draw() {

    // Array to hold the gray values of a patch
    int[] x = new int[patch_w * patch_h];

    // Quantize the image
    for (int i=0; i < (_width/patch_w); ++i) {
        for (int j=0; j < (_height/patch_h); ++j) {
            patch = cropped_img.get(i*patch_w, 
                                    j*patch_h, 
                                    patch_w, 
                                    patch_h);
            patch.loadPixels();
            for (int k=0; k < patch.pixels.length; ++k) {
                x[k] = rgb2gray(patch.pixels[k]);
            }

            int dice_num = six_step_gray(mean(x));
            if (dice_num == 1) draw_one(i, j);
            if (dice_num == 2) draw_two(i, j);
            if (dice_num == 3) draw_three(i, j);
            if (dice_num == 4) draw_four(i, j);
            if (dice_num == 5) draw_five(i, j);
            if (dice_num == 6) draw_six(i, j);      
        }
    }  
}

void draw_one(int i, int j) {
    fill(0);
    rect(i*patch_w, j*patch_h, 16, 16);
    fill(255);
    ellipse(i*patch_w+8, j*patch_h+8, pip_size, pip_size);
}

void draw_two(int i, int j) {
    fill(0);
    rect(i*patch_w, j*patch_h, 16, 16);
    fill(255);
    ellipse(i*patch_w+3, j*patch_h+3, pip_size, pip_size);
    ellipse(i*patch_w+13, j*patch_h+13, pip_size, pip_size);
}

void draw_three(int i, int j) {
    fill(0);
    rect(i*patch_w, j*patch_h, 16, 16);
    fill(255);
    ellipse(i*patch_w+3, j*patch_h+3, pip_size, pip_size);
    ellipse(i*patch_w+8, j*patch_h+8, pip_size, pip_size);
    ellipse(i*patch_w+13, j*patch_h+13, pip_size, pip_size);
}

void draw_four(int i, int j) {
    fill(0);
    rect(i*patch_w, j*patch_h, 16, 16);
    fill(255);
    ellipse(i*patch_w+3, j*patch_h+3, pip_size, pip_size);
    ellipse(i*patch_w+3, j*patch_h+13, pip_size, pip_size);
    ellipse(i*patch_w+13, j*patch_h+3, pip_size, pip_size);
    ellipse(i*patch_w+13, j*patch_h+13, pip_size, pip_size);  
}

void draw_five(int i, int j) {
    fill(0);
    rect(i*patch_w, j*patch_h, 16, 16);
    fill(255);
    ellipse(i*patch_w+3, j*patch_h+3, pip_size, pip_size);
    ellipse(i*patch_w+3, j*patch_h+13, pip_size, pip_size);
    ellipse(i*patch_w+13, j*patch_h+3, pip_size, pip_size);
    ellipse(i*patch_w+13, j*patch_h+13, pip_size, pip_size);
    ellipse(i*patch_w+8, j*patch_h+8, pip_size, pip_size);
}

void draw_six(int i, int j) {
    fill(0);
    rect(i*patch_w, j*patch_h, 16, 16);
    fill(255);
    ellipse(i*patch_w+3, j*patch_h+3, pip_size, pip_size);
    ellipse(i*patch_w+3, j*patch_h+8, pip_size, pip_size);
    ellipse(i*patch_w+3, j*patch_h+13, pip_size, pip_size);
    ellipse(i*patch_w+13, j*patch_h+3, pip_size, pip_size);
    ellipse(i*patch_w+13, j*patch_h+8, pip_size, pip_size);
    ellipse(i*patch_w+13, j*patch_h+13, pip_size, pip_size);
}

// Impose 6 step gray palette
int six_step_gray(int x) {
    if (0 <= x && x <= 41)
        return 1;
    if (41 < x && x <= 83)
        return 2;
    if (83 < x && x <= 124)
        return 3;
    if (124 < x && x <= 165)
        return 4;
    if (165 < x && x <= 206)
        return 5;
    if (x < 206 && x <= 247)
        return 6;
    else
        return 6;
}

// Blend rgb channels
int rgb2gray(int argb) { 
    int _alpha = (argb >> 24) & 0xFF;
    int _red = (argb >> 16) & 0xFF;
    int _green = (argb >> 8 ) & 0xFF;
    int _blue = (argb) & 0xFF;

    return int(0.3*_red + 0.59*_green + 0.11*_blue);
}

// Calculates the average of an integer array
int mean(int[] x) {
    float m = 0;
    for (int i=0; i < x.length; ++i) {
        m += x[i];
    }
    m = m/x.length;  
    return int(m);
}