imagick example base64 in php

$PostImage = $_POST['PostImage'];
$imageBlob = base64_decode(str_ireplace('data:image/png;base64,','',$PostImage));

$im = new Imagick();
$im->readImageBlob($imageBlob);
	//$im = new Imagick($_FILES['imageForPost']["tmp_name"]);
            $imageprops = $im->getImageGeometry();

    $finalWidth = 512;
    $finalHeight = 512;
        
            $ext = '.png';                  
            $size = 100;            
            $name = time().$ext;//$_FILES["image"]["name"];
                          
                $width = $imageprops['width'];
                $height = $imageprops['height'];
                if($height > $finalHeight){
                $newHeight = $finalHeight;
                $newWidth = ($finalHeight / $height) * $width;
                }else{
                $newWidth = $imageprops['width'];
                $newHeight = $imageprops['height'];
                }
                
                $im->scaleImage($finalWidth,$finalHeight,true,true);
                $im->setOption('png:extent', $size.'kb');
				$im->setImageFormat( "png" ); 
				header("Content-Type: image/png");
				echo $im;