Crop resize images on the fly using PHP - php

Question

I'm building a wallpaper website and therefore i need to be able to resize the original image before downloading. I tried this code to resize the image:
//resize and crop image by center
function resize_crop_image($max_width, $max_height, $source_file, $dst_dir, $quality = 80){
$imgsize = getimagesize($source_file);
$width = $imgsize[0];
$height = $imgsize[1];
$mime = $imgsize['mime'];
switch($mime){
case 'image/gif':
$image_create = "imagecreatefromgif";
$image = "imagegif";
break;
case 'image/png':
$image_create = "imagecreatefrompng";
$image = "imagepng";
$quality = 7;
break;
case 'image/jpeg':
$image_create = "imagecreatefromjpeg";
$image = "imagejpeg";
$quality = 80;
break;
default:
return false;
break;
}
$dst_img = imagecreatetruecolor($max_width, $max_height);
$src_img = $image_create($source_file);
$width_new = $height * $max_width / $max_height;
$height_new = $width * $max_height / $max_width;
//if the new width is greater than the actual width of the image, then the height is too large and the rest cut off, or vice versa
if($width_new > $width){
//cut point by height
$h_point = (($height - $height_new) / 2);
//copy image
imagecopyresampled($dst_img, $src_img, 0, 0, 0, $h_point, $max_width, $max_height, $width, $height_new);
}else{
//cut point by width
$w_point = (($width - $width_new) / 2);
imagecopyresampled($dst_img, $src_img, 0, 0, $w_point, 0, $max_width, $max_height, $width_new, $height);
}
$image($dst_img, $dst_dir, $quality);
if($dst_img)imagedestroy($dst_img);
if($src_img)imagedestroy($src_img);
}
And this will do the resize:
resize_crop_image($width, $height, $image_URL, $save_URL)
This code works fine for me but i want to ONLY send the output to user's browser, since saving thousands of extra images isn't possible. There are libraries i can use, but i don't want to use a third party snippet. Is there a way to alter this code in the way i desire?
Thanks.

Answer 1

For your $image function , do not specify a destination directory (null) and an image stream will be created.
header("Content-type:{$mime}");
That should send the image to the user

Answer 2

You just need to set the proper headers and echo the output. Every PHP request "downloads a file" to the browser, more or less. You just need to specify how the browser handles it. So try something like:
header("Content-Type: $mime");
header("Content-Disposition: attachment; filename=$dst_img");
echo $dst_img;
That should do it for you.