试图在本地上传1M文件，我收到致命错误

Question

"Fatal error: Allowed memory size of 31457280 bytes exhausted (tried to allocate 9828 bytes)".

This is the error i get but I am only trying to upload a 1mb image. I have increased the memory limit in php.ini and the execution time. I am trying this on a local MAMP server, on a Mac using firefox. This going to be for an online image gallery. Any ideas? Below is the code:

    ini_set("memory_limit","30M");
    if(isset($_POST['submit'])){
      if (isset ($_FILES['new_image'])){
          $imagename = $_FILES['new_image']['name'];
          $source = $_FILES['new_image']['tmp_name'];
          $target = "images/".$imagename;
          move_uploaded_file($source, $target);

          $imagepath = $imagename;
          //below here for the removed code


          $save = "thumbs/uploads/" . $imagepath; //This is the new file you saving
          $file = "images/" . $imagepath; //This is the original file
          $imagesize = getimagesize($file);

          list($width, $height) = $imagesize; 

          unset($imagesize);

          if($width>$height)
            {
                $modwidth = 150; 
                $diff = $width / $modwidth;
                $modheight = $height / $diff;
            }else{
                $modheight = 150; 
                $diff = $height / $modheight;
                $modwidth = $width / $diff;
            }
          $tn = imagecreatetruecolor($modwidth, $modheight); 
          $image = imagecreatefromjpeg($file); 
          $imagecopy = imagecopyresampled($tn, $image, 0, 0, 0, 0, $modwidth, $modheight, $width, $height); 

          imagedestroy($image);
          imagedestroy($im);
          imagedestroy($imagecopy);
          imagedestroy($source);

          $imagejpg = imagejpeg($tn, $save, 100); 
            imagedestroy($tn);
          imagedestroy($imagejpg);

---

EDIT

This has now been sorted out hopefully. One of my colleagues had a solution all along but neglected to tell me!

Answer 1

You're likely loading the image to do some manipulation of it. That causes the image data to be decompressed, which requires a lot of memory for big images (I think it's about 4 bytes per pixel).

You can choose to either not process the image, or do your processing outside of PHP - for example by invoking ImageMagick or some other program. It depends a bit on what you're trying to accomplish.

Answer 2

It's nothing to do with the (file)size of the image you're uploading, the call that's breaking your memory limit is imagecreatetruecolor().

imagecreatetruecolor() will allocate an area of memory to store a true colour image in with no compression, and use 32 bits (4 bytes) per pixel.

So for a 1024x768 pixel image, for example, imagecreatetruecolour() will use up 1024*768*4 = 3145728 bytes, or around 3MB.

The problem is that this scales up quite dramatically. A 3072x2034 (6 megapixel) image, by the same sort of calculation, needs around 24MB just to be loaded into memory - I would guess this is the sort of size you're dealing with.

The solution is to hand off the processing to something else like imagemagick or NetPBM that will run as a separate process and not count towards the PHP memory limit.

NetPBM is my personal favourite and would look something like:

anytopnm <file> | pnmscale -xysize <dimensions> | pnmtojpg  > <outfile> 

Answer 3

As mentioned here :

don't forget the imagedestroy () function, or caching your thumbnails - they'll save you a LOT of work down the road.

Answer 4

Did you restart apache after you increased the memory limit? If yes, then increase a little more.