# Dynamic image using PHP

I need to create an image on the fly where one large image covers a small image. The large image is a mask which makes the underlying image visible. Here is a quick sketch of what I'm trying to accomplish:

It's important that Y lies beneath X.

I have created to code for this and it works, but I was wondering how I can make the code more efficient. This is what I have:

    // Create a blank image with the underlying image correctly positioned
$blank = imagecreatetruecolor(403, 403);$profile = imagecreatefromjpeg('img.jpg');
$w = imagesx($profile);
$h = imagesy($profile);
imagecopy($blank,$profile, 0, 140, 0, 0, $w,$h);
imagejpeg($blank, 'tmp.jpg', 100); // Frame overlay$frame = imagecreatefrompng('frame.png');
$photo = imagecreatefromjpeg('tmp.jpg'); imagecopy($photo, $frame, 0, 0, 0, 0, 403, 403); imagejpeg($photo, 'output.jpg', 100);

// Garbage collection
imagedestroy($blank); imagedestroy($profile);
imagedestroy($frame); imagedestroy($photo);


I just think that creating 2 different images is just overkill, but I just can't find a better solution.

• How long does your code take to run? Would there be any benefit in finding another method? (In other words, are you trying to over-optimise?) – DaveP Aug 13 '12 at 13:04
• Well, the code runs pretty fast. It's just that I'd like to know if the final image could be created with only 1 imagecopy call (or with something else). I'll post this question on the codereview page you gave me Aleks, thanks. – priktop Aug 13 '12 at 13:15
• First off, a disclaimer: I've never used any of these functions before. But it seems to me that instead of recreating the same base image every time, it might be better to create a permanent one in a "template" directory, then load it whenever you need it. Then you can make what ever changes you need and save it to the permanent directory. But this is all speculation. – mseancole Aug 13 '12 at 19:11

First of all don't save your temporary file as tmp.jpg, think about what happends if there are 2 requests for an image at the same time, the first tmp.jpg will be overwritten by the second one (very unlikely, but still possible and very hard to debug / reproduce bug)..

Second saving to the disk is expensive and useless, avoid it whenever possible.

Third why do you need the blank image? I think you should have the frame image and overlay the profile image on top of it.

Given this, I think the code should look like this:

// Create a blank image with the underlying image correctly positioned
$base = imagecreatefrompng('frame.png');$profile = imagecreatefromjpeg('img.jpg');
$w = imagesx($profile);
$h = imagesy($profile);
imagecopy($base,$profile, 0, 140, 0, 0, $w,$h);

imagejpeg($base, 'output.jpg', 100); // Garbage collection imagedestroy($base);
imagedestroy(\$profile);


Unless I miss something this code should do exactly the same thing, but faster and safer.