Added code to generate colored concentric rings based on the pixels i…

…n a source image

rings/ring.php

@@ -0,0 +1,118 @@
+<?php
+/*
+Brian Suda
+brian@suda.co.uk
+
+This will take an image and parse through all the pixels and attempt to make a nice circular representation.
+
+This is an idea similar to http://hint.fm/projects/wired2008/
+
+More about the process can be read about on netmagazine.com
+
+Usage:
+php ring.php > output.svg
+*/
+
+// Fetch the JPEG image from a file
+$im = imagecreatefromjpeg("example.jpg");
+
+// use the built-in color palette reducer instead of the reduceColors()
+// imagetruecolortopalette($im,true,20);
+
+// Get the height and width based on the x,y values
+$x = imagesx($im);
+$y = imagesy($im);
+
+$rgb = array();
+$counter = 0;
+$scaler = 30;
+
+// get colour count frequency by looping through the image column by column
+for($i=0;$i<$x;$i++){
+  for($j=0;$j<$y;$j++){
+	// get that pixel's RGB value and store it in an array
+    $rgb[imagecolorat($im, $i, $j)]++;
+  }
+}
+
+// Sort the array
+asort($rgb);
+
+// We don't need the source image any more
+imagedestroy($im);
+
+// Using our own color merging algorithm, we'll find nearly the same value color and merged them
+$rgb = reduceColors($rgb);
+
+header('Content-Type: image/svg+xml');
+
+echo '<?xml version="1.0" standalone="no"?>
+<!DOCTYPE svg PUBLIC "-//W3C//DTD SVG 1.1//EN"
+"http://www.w3.org/Graphics/SVG/1.1/DTD/svg11.dtd">
+
+<svg width="100%" height="100%" version="1.1"
+xmlns="http://www.w3.org/2000/svg">';
+
+// Set the center
+$c = (int)(($x*$y)/$scaler);
+$prev = 0;
+
+foreach($rgb as $k=>$v){
+  if($v > 0) {
+    $r = ($k >> 16) & 0xFF;
+    $g = ($k >> 8) & 0xFF;
+    $b = $k & 0xFF;
+
+	// convert each RGB value into a hex color
+    $hex = str_pad(dechex($r),2,'0',STR_PAD_LEFT).str_pad(dechex($g),2,'0',STR_PAD_LEFT).str_pad(dechex($b),2,'0',STR_PAD_LEFT);
+
+	// stack the circles onto of one another as they gradually get smaller
+    echo '<circle cx="'.$c.'" cy="'.$c.'" r="'.($c-$prev).'" fill="#'.$hex.'" />'."\n";
+    $prev += (int)($v/$scaler);
+
+  }
+}
+
+echo '</svg>';
+
+function reduceColors($rgb){
+	// if you want more rings, adjust the $plusminus to taste
+	$plusminus = 50;
+	arsort($rgb);	
+	$temp = array();
+	// do colour merger
+	foreach($rgb as $k=>$v){
+	  if($v != 0){
+	    $r = ($k >> 16) & 0xFF;
+	    $g = ($k >> 8) & 0xFF;
+	    $b = $k & 0xFF;
+
+		$matched = false;
+	    foreach($temp as $m=>$n){
+	      if($m != $k){
+	        $rs = ($m >> 16) & 0xFF;
+	        $gs = ($m >> 8) & 0xFF;
+	        $bs = $m & 0xFF;
+
+	        if (
+	          ($rs <= ($r+$plusminus))&&($rs >= ($r-$plusminus)) &&
+	          ($gs <= ($g+$plusminus))&&($gs >= ($g-$plusminus)) &&
+	          ($bs <= ($b+$plusminus))&&($bs >= ($b-$plusminus)) &&
+			  $matched == false
+	          ) {
+	  				$temp[$m] += $v;
+					$matched = true;
+	        }
+	      }
+	    }
+		if(!($matched)){
+			$temp[$k] = $v;
+		}
+	  }
+	}
+
+	asort($temp);
+	return $temp;
+}
+
+?>