PHP内存限制25MB耗尽 - 文件上载/裁剪/调整大小

Question

我正在使用单个图像上传/裁剪/调整大小脚本来处理高达10MB的文件.

在测试时,我将php_ini内存限制设置为25M,并且在上传文件时仅耗尽大约1.4MB.

"Allowed memory size of 26214400 bytes exhausted (tried to allocate 10368 bytes)"

这对我来说很奇怪,不是10368 <26214400？(修辞问题)

或者这是否意味着我超过25MB的10368字节？我的脚本应该使用这么多内存吗？

码:

function make_thumbnails($updir, $img)
{
    $thumbnail_width    = 200;
    $thumbnail_height   = 150;
    $thumb_preword  = "thumb_";

    $arr_image_details  = GetImageSize($updir.$img);
    $original_width = $arr_image_details[0];
    $original_height    = $arr_image_details[1];

    if( $original_width > $original_height ){
        $new_width  = $thumbnail_width;
        $new_height = intval($original_height*$new_width/$original_width);
    } else {
        $new_height = $thumbnail_height;
        $new_width  = intval($original_width*$new_height/$original_height);
    }

    $dest_x = intval(($thumbnail_width - $new_width) / 2);
    $dest_y = intval(($thumbnail_height - $new_height) / 2);

    if($arr_image_details[2]==1) { $imgt = "ImageGIF";  $imgcreatefrom = "ImageCreateFromGIF";  }
    if($arr_image_details[2]==2) { $imgt = "ImageJPEG"; $imgcreatefrom = "ImageCreateFromJPEG";  }
    if($arr_image_details[2]==3) { $imgt = "ImagePNG";  $imgcreatefrom = "ImageCreateFromPNG";  }

    if( $imgt )
    {
        $old_image = $imgcreatefrom($updir.$img);
        $new_image = imagecreatetruecolor($thumbnail_width, $thumbnail_height);
        imageCopyResized($new_image,$old_image,$dest_x,
        $dest_y,0,0,$new_width,$new_height,$original_width,$original_height);
        $imgt($new_image,$updir.$thumb_preword.$img);

        // Added by your suggestions:
         imagedestroy($old_image);
         imagedestroy($new_image);
    }
}

Answer 1

除了已经说过的话:

永远不要忘记处理压缩文件格式(如JPEG)需要比实际文件大小更多的内存.一个3000 x 3000像素JPG文件只能重500kb,但需要(大致)3000 x 3000 x 3(红色,绿色和蓝色各一个字节,依赖于模式甚至Alpha的一个字节)=至少27 MB .