PHP: Convert SVG image to PNG

$usmap = '/path/to/blank/us-map.svg';
$im = new Imagick();
$svg = file_get_contents($usmap);

/*loop to color each state as needed, something like*/ 
$idColorArray = array(
     "AL" => "339966"
    ,"AK" => "0099FF"
    ...
    ,"WI" => "FF4B00"
    ,"WY" => "A3609B"
);

foreach($idColorArray as $state => $color){
//Where $color is a RRGGBB hex value
    $svg = preg_replace(
         '/id="'.$state.'" style="fill:#([0-9a-f]{6})/'
        , 'id="'.$state.'" style="fill:#'.$color
        , $svg
    );
}

$im->readImageBlob($svg);

/*png settings*/
$im->setImageFormat("png24");
$im->resizeImage(720, 445, imagick::FILTER_LANCZOS, 1);  /*Optional, if you need to resize*/

/*jpeg*/
$im->setImageFormat("jpeg");
$im->adaptiveResizeImage(720, 445); /*Optional, if you need to resize*/

$im->writeImage('/path/to/colored/us-map.png');/*(or .jpg)*/
$im->clear();
$im->destroy();

The steps regex color replacement may vary depending on the SVG path xml and how you id & color values are stored. If you don't want to store a file on the server, you can output the image as base 64 like

<?php echo '<img src="data:image/jpg;base64,' . base64_encode($im) . '"  />';?>

(before you use clear/destroy) but ie has issues with PNG as base64 so you'd probably have to output base64 as jpeg

you can see an example here I did for a former employer's sales territory map:

Start: http://upload.wikimedia.org/wikipedia/commons/3/32/Blank_US_Map.svg