The code first draws the main cake rectangle. After that, it loops three times to draw the rectangles for the candlesticks, polygons for the flames, then orange circles with an alpha channel for the light. It finishes off with a series of lines whose lengths are determined by the sine function, used for the frosting.

Here’s the output.

<?php               header             ('Content'.
'-type:'.          'image/png'         );$f = 'im'.
'agecre'.          'atetrueco'.        'lor';$im=$f
(250,250);         $g='imagef'.        'illedrect'.
'angle';$g         ($im,10,120,        240,240,(630*
10000)+ 37         *100+44);for        ($i=0;$i<3;$i
++){$x=60+         $i*60;$g($im        ,$x+2,50,$x+8,
120,0xeeeeee);$h=str_rot13('vzntrsvyyrqcbyltba');$h(
$im,array($x,50,$x+5,30,$x+10,50),3,0xc00000);$h($im,
array($x+2,50,$x+ 5,40,$x+8,50),3, 0xff8000);$h ($im,
array($x+3,50,$x+5,45,$x+7,50),3,0x0000ff);$el='ima'.
'gefilledellipse';$el($im,$x+5,40,40,40,0x48ffa000);}
$l='i'.'m'.'a'. 'g'.'e'.'l'.'in'.'e';$c=0xd0d0ff; for
($i=10;$i<=240;$i++){$y=130+3* sin(($i-10)/2);$l($im,
$i,120,$i,$y,$c);}$p=strrev('egami').'png';$d='imag';
$d.='ede';$de='str';$d.=$de;$d.='oy';$p($im);$d($im);

Unobfuscated version:

<?php

header('Content-type: image/png');
$img = imageCreateTrueColor(250, 250);
imageFilledRectangle($img, 10, 120, 240, 240, 0x603000);

// loop through the 3 candles
for ($i = 0; $i < 3; $i++) {
	$x = 60 + $i * 60;
	// candlestick, red flame, orange flame, blue flame, light
	imageFilledRectangle($img, $x + 2, 50, $x + 8, 120, 0xEEEEEE);
	imageFilledPolygon($img, array($x, 50, $x + 5, 30, $x + 10, 50), 3, 0xC00000);
	imageFilledPolygon($img, array($x + 2, 50, $x + 5, 40, $x + 8, 50), 3, 0xFF8000);
	imageFilledPolygon($img, array($x + 3, 50, $x + 5, 45, $x + 7, 50), 3, 0x0000FF);
	imageFilledEllipse($img, $x + 5, 40, 40, 40, 0x48FFA000);
}

// frosting
for ($i = 10; $i <= 240; $i++) {
	$y = 130 + 3 * sin(($i - 10) / 2);
	imageLine($img, $i, 120, $i, $y, 0xD0D0FF);
}

imagePNG($img);
imageDestroy($img);

Going more in-depth, the code uses polar coordinates to draw a cardioid-like figure, which are converted into cartesian coordinates via the cfp_x() and cfp_y() functions. The new coordinates are then used in PHP’s imageFilledPolygon() function to draw the shape.

The formula to create the heart is simply done by setting the radius equal to the angle, rotated 90 degrees so that the shape is right-side up. So, at 0, the coordinates are at the origin – the sharp valley of the heart. At 180, the coordinates are at the bottom point of the heart.

View the output here.

           function                cfp_x($ox,
     $a,$d) {return ($ox+    round((cos (deg2rad($a
   ))*$d)));}function cfp_y($oy, $a, $d){return ($oy+
  round((sin(deg2rad($a)) * $d)));} $crd=array();$ct=0;
 $im=imageCreateTrueColor(250,250);$c=imageColorAllocate
 ($im,255,0,0);header("Content-type: image/png");for($i
  =-180;$i<180;$i++){$crd[]=cfp_x(125,$i -90,abs($i));
    $crd[] = cfp_y(50, $i - 90, abs($i) ); $ct++;}
        imageFilledPolygon($im, $crd,$ct,$c);
            imagePNG($im);imageDestroy
                      (($im));
                         ?>

Unobfuscated version:

function cfp_x($origin_x, $angle, $radius) {
    return $origin_x + round(cos(deg2rad($angle)) * $radius);
}
function cfp_y($origin_y, $angle, $radius) {
    return $origin_y + round(sin(deg2rad($angle)) * $radius);
}

$coords = array();
$num_pts = 0;
$img = imageCreateTrueColor(250, 250);

for ($i = -180; $i < 180; $i++) {
    $coords[] = cfp_x(125, $i - 90, abs($i));
    $coords[] = cfp_y(50, $i - 90, abs($i));
    $num_pts++;
}

imageFilledPolygon($img, $coords, $num_pts, 0xFF0000);
header('Content-type: image/png');
imagePNG($img);
imageDestroy($img);