imagejpeg

(PHP 3 >= 3.0.16, PHP 4, PHP 5)

imagejpeg -- 以 JPEG 格式将图像输出到浏览器或文件

说明

bool imagejpeg ( resource image [, string filename [, int quality]] )

imagejpeg()image 图像以 filename 为文件名创建一个 JPEG 图像。image 参数是 imagecreatetruecolor() 函数的返回值。

filename 参数为可选,如果省略,则原始图像流将被直接输出。要省略 filename 参数而提供 quality 参数,使用空字符串('')。通过 header() 发送 Content-type: image/jpeg 可以使 PHP 脚本直接输出 JPEG 图像。

注: JPEG 支持仅在 PHP 与 GD-1.8 或更高版本一起编译时可用。

quality 为可选项,范围从 0(最差质量,文件更小)到 100(最佳质量,文件最大)。默认为 IJG 默认的质量值(大约 75)。

如果想输出渐进式 JPEG,需要用 imageinterlace() 函数将隔行扫描比特置位。

参见 imagepng()imagegif()imagewbmp()imageinterlace()imagetypes()


add a note add a note User Contributed Notes
webmaster at jongliertreff dot de
25-Aug-2006 07:56
Here's another on-the-fly thumbnail creation script.
When I scripted the pictuerviewer on my page, I had all the pictures only in full size and qualit, because I wanted the posibility fr visitors to download the pictures.
But as Imagesizes of more than 4 MP are to large for websites, I created thumbnails and the smaller pictures on the fly. But I found out, that the Script needed too much RAM, especially in the thumbnail overview, when I had more then 50 thumbnails to create on the fly at the same time.

So I modified my image creator and my viewer to let them store images, that are created. So only the first visitor has to wait (which is usually me for controlling the uploads und updates), all other visitors get the stored images, which is much faster.

Create different folders. I have a main folder called 'imagesdb' and the tree subfolders full (Full quality images), show (images for the picture viewer) and thumb (for thumbnails in overview).

Store the script for example as image.php and link it like that:

<?PHP
$image_name
= "foo.jpg";
$style = "show";
    
// I've taken the foldernames. It's easier. For the
     //thumbnails replace "show" with "thumb".
$image_name = "imagesdb/$style/$image_name";
if(!
file_exists($image_name))
      
$image_name = "image.php?image_name=$image_name&style=$style";
    
// only if file doesn't exist call the on-the-fly creating file
?>

Now the main script, stored in the file image.php:

<?PHP

$image_name
= $_GET['image_name'];
$style = $_GET['style'];

    
// Now set the maximum sizes to the different styles.
     // You may set additional styles, but remember to
     // create the according subfolders.

switch($style) {
  case
"show":
  
$max_size = 800;
   break;
  case
"thumb":
  
$max_size = 125;
}

$dest_file = "imagesdb/$style/$image_name";
    
// set output file
$image_file = "imagesdb/full/$image_name";
    
// set source file
$size = getimagesize($image_file);
    
// get original size

if($size[0] > $size[1]) {
 
$divisor = $size[0] / $max_size;
}
else {
 
$divisor = $size[1] / $max_size;
}
    
// to get allways pictures of the same size, which ist
     // mostly wanted in imageviewers, look what ist larger:
     // width or height

$new_width = $size[0] / $divisor;
$new_height = $size[1] / $divisor;
    
// set new sizes

settype($new_width, 'integer');
settype($new_height, 'integer');
    
// sizes should be integers

$image_big = imagecreatefromjpeg($image_file);
    
// load original image
$image_small = imagecreatetruecolor($new_width, $new_height);
    
// create new image
imagecopyresampled($image_small, $image_big, 0,0, 0,0, $new_width,$new_height, $size[0],$size[1]);
    
// imageresampled whill result in a much higher quality
     // than imageresized
imagedestroy($image_big);
    
// the original data are no longer used

header("Content-type: image/jpeg");

if(
$style=="show" || $style=="thumb") {
  if(!
file_exists($dest_file))
  
imagejpeg($image_small, $dest_file, 100);
}
    
// if you have set additional sizese put them in the
     // if-arguments, too.
     // if someone calls the image.php directly in the
     // browser with imagenames allready existing, they
     // won't be overwritten

imagejpeg($image_small, '', 100);
imagedestroy($image_small);
    
// finally send image to browser and destroy no longer
     // needed data.

?>

As this website helped me for several times in the past and for creating this script, I hope I can help others with this script saving the time for developing a much more performant solution than an allways-on-the-fly-creating script.
chris dot calo at gmail dot com
24-Jul-2006 10:30
Thanks to Stuart and Darren for the corrections to the create_thumbnail function.  Another note on that function: imagecreatefromwbmp was incorrectly used.  WBMPs are wireless bitmaps, not windows bitmaps (thanks to clambert at whitecrown), so the thumbnail routine as is will not be able to handle windows bitmaps.  See the notes at http://us2.php.net/manual/en/function.imagecreatefromwbmp.php for tips on working with windows bitmaps.
stuart at purpletoucan dot com
24-Jul-2006 01:55
Thanks to Chris dot Calo for the thumbnail snippet.  The file type issue is easily resolved by getting the type from the file with getimagesize, and you can handle unsupported types at that stage too.  Thus:

   list($img_width,$img_height, $type) = getimagesize($source_file); // Get the original dimentions
   if ($type != 1 && $type != 2 && $type != 3 && $type != 15) { die("Your file is not a supported format"); }

...and then later check the type again to open the image correctly:

   if ( $type == 1 ) { $img_source = imagecreatefromgif($source_file); }
   else if ( $type == 2 ) { $img_source = imagecreatefromjpeg($source_file); }
   else if ( $type == 3 ) { $img_source = imagecreatefrompng($source_file); }
   else if ( $type == 15 ) { $img_source = imagecreatefromwbmp($source_file); }
Darren Kulp ( kulp at thekulp dot com )
19-Jul-2006 11:47
With regard to chris.calo's code:

// The following block retrieves the source file.  It assumes the filename extensions match the file's format.
   if ( strpos($source_file,".gif") ) { $img_source = imagecreatefromgif($source_file); }
   if ( (strpos($source_file,".jpg")) || (strpos($source_file,".jpeg")) )
 ... etc.

It assumes more than that, namely that the filename does not contain the strings '.gif', '.jpg', '.jpeg', '.bmp', or '.png' *anywhere* in the string. Some valid files with special filenames could break this; for example, a file named "used.to.be.a.png.file.gif" would cause this script to attempt to load the file as a PNG. Obviously this is a rare case, but the issue could be easily avoided by using "else ifs" (uses less CPU time) or checking that the extension abuts the end of the string or both.

That said, the whole business could be avoided if PHP didn't clutter the namespace with different functions to do the same thing with different image formats. Ick.
chris dot calo at gmail dot com
18-Jul-2006 05:44
function create_thumbnail( $source_file, $destination_file, $max_dimension)
{
   list($img_width,$img_height) = getimagesize($source_file); // Get the original dimentions
   $aspect_ratio = $img_width / $img_height;
  
   if ( ($img_width > $max_dimension) || ($img_height > $max_dimension) ) // If either dimension is too big...
   {
       if ( $img_width > $img_height ) // For wide images...
       {
           $new_width = $max_dimension;
           $new_height = $new_width / $aspect_ratio;
       }
       elseif ( $img_width < $img_height ) // For tall images...
       {
           $new_height = $max_dimension;
           $new_width = $new_height * $aspect_ratio;
       }
       elseif ( $img_width == $img_height ) // For square images...
       {
           $new_width = $max_dimension;
           $new_height = $max_dimension;
       }
       else { echo "Error reading image size."; return FALSE; }
   }
   else { $new_width = $img_width; $new_height = $img_height; } // If it's already smaller, don't change the size.
  
   // Make sure these are integers.
   $new_width = intval($new_width);
   $new_height = intval($new_height);
  
   $thumbnail = imagecreatetruecolor($new_width,$new_height); // Creates a new image in memory.

   // The following block retrieves the source file.  It assumes the filename extensions match the file's format.
   if ( strpos($source_file,".gif") ) { $img_source = imagecreatefromgif($source_file); }
   if ( (strpos($source_file,".jpg")) || (strpos($source_file,".jpeg")) )
   { $img_source = imagecreatefromjpeg($source_file); }
   if ( strpos($source_file,".bmp") ) { $img_source = imagecreatefromwbmp($source_file); }
   if ( strpos($source_file,".png") ) { $img_source = imagecreatefrompng($source_file); }
  
   // Here we resample and create the new jpeg.
   imagecopyresampled($thumbnail, $img_source, 0, 0, 0, 0, $new_width, $new_height, $img_width, $img_height);
   imagejpeg( $thumbnail, $destination_file, 100 );
  
   // Finally, we destroy the two images in memory.
   imagedestroy($img_source);
   imagedestroy($thumbnail);
}
your [dot] sheepy [at] gmail [dot] com
03-Apr-2006 04:34
Regarding Carl Gieringer's comment, it is possible to have PHP files in utf-8.  Just make sure the editor does not output BOM, which is unnecessary in utf-8 anyway.

Except for any editors from Microsoft, most programmer's editors that supports utf allows you to surpress BOM.
doobd at doobd dot com
16-Feb-2006 01:48
in addition to my THUMBNAIL GENERATOR script:

i forgot to say, src path must not be http:// but server path (e.g. for some linux server: src=/home/users/user1/public_html/images/image1.jpg) or relative path, as in example in script (src=test.jpg, src=../test.jpg, src=pictures/test.jpg...)
15-Feb-2006 11:44
THUMBNAIL GENERATOR

Hope someone will find this usefull... save it to thumb.php and use it for on-the-fly thumbnails generating

e.g.
<img src= "thumb.php?src=pic.jpg&wmax=150&hmax=100&quality=90&bgcol=FF0000"> </img>

<?php
  
// by dooobd@NOSPAM.doobd.com
   //
   // proportional on-the-fly thumb generator from JPG images
   //
   // usage example:
   // <img src= "thumb.php?src=pic.jpg&wmax=150&hmax=100&quality=90&bgcol=FF0000"> </img>
   //
   // parameters:  src = source image
   //              wmax = max width
   //              hmax = max height
   //              quality = JPG quality of generated thumb - optional.
   //                        if not specified, quality=90
   //              bgcol = if specified, allways generates exact wmax x hmax sized thumb,
   //                      with bacground color bgcol and centered source image
   //
   // note: if source image is smaller than desired thumbnail, it will not be resized!

  
header("Content-type: image/jpeg");
  
$source = imagecreatefromjpeg($src);
  
$orig_w=imagesx($source);
  
$orig_h=imagesy($source);
  
   if (
$orig_w>$wmax || $orig_h>$hmax)
   {
      
$thumb_w=$wmax;
      
$thumb_h=$hmax;
       if (
$thumb_w/$orig_w*$orig_h>$thumb_h)
          
$thumb_w=round($thumb_h*$orig_w/$orig_h);
       else
          
$thumb_h=round($thumb_w*$orig_h/$orig_w);
   } else
   {
      
$thumb_w=$orig_w;
      
$thumb_h=$orig_h;
   }
   if (!@
$bgcol)
   {
      
$thumb=imagecreatetruecolor($thumb_w,$thumb_h);
      
imagecopyresampled($thumb,$source,
                          
0,0,0,0,$thumb_w,$thumb_h,$orig_w,$orig_h);
   }
   else
   {
      
$thumb=imagecreatetruecolor($wmax,$hmax);
      
imagefilledrectangle($thumb,0,0,$wmax-1,$hmax-1,intval($bgcol,16));
      
imagecopyresampled($thumb,$source,
                          
round(($wmax-$thumb_w)/2),round(($hmax-$thumb_h)/2),
                          
0,0,$thumb_w,$thumb_h,$orig_w,$orig_h);
   }
   if (!@
$quality) $quality=90;
  
imagejpeg($thumb,"",$quality);
  
imagedestroy($thumb);
?>
08-Feb-2006 02:21
This extension allows to save frames from movie files as jpeg.

http://ffmpeg-php.sourceforge.net
valentinp at gmail dot com
07-Jan-2006 10:41
For all those people getting the

"Warning: imagejpeg(): Unable to access data ..."

I solved it by chmodding the directory you're writing to, to 0777.

NO fopen() needed!

Regards,
Valentin
03-Jan-2006 09:59
Hi

I had similar problem with safe mode. My solution is:

before imagejpeg(), touch() etc.
write:
ini_set(safe_mode,Off);
and after everything:
ini_set(safe_mode,On);

strange, but it works
Chears2All
aerowinx at hotmail dot de
22-Dec-2005 07:26
If imagejpeg brings up this warning:

Warning: imagejpeg(): Unable to access data ...

it could be a problem with "Safe Mode". A solution could be to touch the new file before, like:

touch($newfile);
imagejpeg($image_p, $newfile, 100);
Kenneth Keiter
18-Dec-2005 12:59
So.. after messing around with this beast of a function for hours, I discovered that it DOES NOT preserve the resource it is using the create the image, nor do imagepng() or imagegif(). By this I mean that you can not run two imagejpeg(), imagepng() or imagegif() calls on the same resource. Another possibly undocumented quirk... :-(
I_have at no_email_for_spam dot com
03-Nov-2005 01:01
The behaviour of not being allowed to write the file is based on a change in latest release, see http://www.php.net/ChangeLog-4.php#4.4.1

- Added missing safe_mode checks for image* functions and cURL.
- ...

Some people (including me) consider this new behaviour as broken, see also http://bugs.php.net/bug.php?id=35060 - please vote for/against the bug if you feel same/different.

Workaround is e.g. a touch($filename); before the imagejpeg($im,$filename);
moron at industrial dot org
03-Nov-2005 12:12
Please note that there is a bug report open for the currently broken safe_mode behaviour on this function:

http://bugs.php.net/?id=35060

According to the PHP staffer who has responded the docs are wrong (I don't agree but I'm also not their employee). 

The work around is to use touch() (or any other file system function that can do this) to create the file first before using imagejpeg().
mitnick at cc dot lv
02-Nov-2005 06:26
i had the same problem as tobylewis had

when i tried to call imagejpeg(), width porperly parameters given it displayed
imagejpeg(): Unable to access usr/home/public_html/pic1.jpg

imho if not correctly configured server this function is not allowed to create the file on disk.

the workaround however is if you create the file using some other function, before call imagejpeg(). something like this

<?
$fh
=fopen($file_name_dest,'w');
fclose($fh);
imagejpeg($dest,$file_name_dest, $quality); 
?>
mbailey [at] aethon [dt] co [dt] uk
19-Sep-2005 04:46
>>Bram Van Dam's

note below is missing "()" from the ob_end_clean call:

ob_end_clean; // stop this output buffer

should read

ob_end_clean(); // stop this output buffer

You can then use this for adding content-length headers (for example flash requires a content length in advance to create loaders)

e.g.

...

ob_start(); // start a new output buffer
   imagejpeg( $newimage, "", 90 );
   $ImageData = ob_get_contents();
   $ImageDataLength = ob_get_length();
ob_end_clean(); // stop this output buffer

header("Content-type: image/jpeg") ;
header("Content-Length: ".$ImageDataLength);
echo $ImageData;

...
(enVide neFelibata) envide at tugamail dot com
28-Aug-2005 10:32
Every script I was writing was giving me an error.
When writing the following code I was able, as a client, to browse the website and save the images (Save image as...) with IE. Yet with Firefox and family the browser tried to save them as 'script_name.php' instead of 'image_name.jpg'.

<?php
   header
("Content-Type: image/jpeg");
  
imagejpeg($image,'',100); // Output to Browser
?>

After trying to save all the watermarked images or saving the image as 'temp.jpg' before outputing it to user, I've read this topic on BugZilla that advised to add the following header:

<?php
   header
("Content-Type: image/jpeg");
  
header("Content-Disposition: attachment; filename=image_name.jpg"); // THIS ONE
?>

Sorry about the English.
Bram Van Dam
20-Aug-2005 03:50
If you wish to capture the jpg data into a variable, rather than outputting it or saving it into a file (perhaps so you can put it in a database), you might want to consider output buffering. Something along these lines should work:

<?php
ob_start
(); // start a new output buffer
  
imagejpeg( $newimage, NULL, 100 );
  
$ImageData = ob_get_contents();
ob_end_clean; // stop this output buffer
?>
John Luetke <johnl1479 gmail com>
06-Aug-2005 08:53
Rewrote the manual example into this function for creating a thumbnail image:

function thumbnail_jpeg ($original, $thumbnail, $width, $height, $quality) {
  list($width_orig, $height_orig) = getimagesize($original);
  if ($width && ($width_orig < $height_orig)) {
   $width = ($height / $height_orig) * $width_orig;
  }
       else {
   $height = ($width / $width_orig) * $height_orig;
  }
  $image_p = imagecreatetruecolor($width, $height);
  $image = imagecreatefromjpeg($originial);
  imagecopyresampled($image_p, $image, 0, 0, 0, 0, $width, $height, $width_orig, $height_orig);
  imagejpeg($image_p, $thumbnail, $quality);
  return;
}
tobylewis at mac dot com
24-Jun-2005 10:04
After trying to get imagejpeg (and imagegif and imagepng) to save an image to a file for some time, it finally dawned on me that perhaps the function would not automatically create the file named in the second parameter.

I then used fopen to create a file prior to the call to imagejpeg and the image was successfully written to the file.  It did not seem to matter if fclose was called before or after the call to imagejpeg.

I also tried to create a file outside of php and use it as the target for output, but this initially failled because of permissions.  Once I set all write permissions on this also accepted output from imagejpeg.
ghokanso at cs dot ndsu dot edu
09-Jun-2005 12:54
When displaying an image using imagepng or imagejpeg, you may want/need to call "header("Content-type: image/jpeg")" before the imagepng and imagejpeg functions.
It appears that some servers/browers are striping out the default header so the image is not rendered and appears as raw data.
(Firefox 1.02+ and OSX Safari for example)
wojteksw at go2 dot pl
04-Apr-2005 06:37
I have changed one line in the script of Kokesh
25-Jun-2004 06:42 listed above, and now it generates better quality thumbnails.
You have to change function imagecopyresized() to imagecopyresampled()
nerdgirl at HATE_SPAMnerdgirl dot dk
28-Feb-2005 04:31
Here is an example of uploading an image, changing its size (width/height) and saving it to a new file. It uses ftp to upload both the original and the resized image. This is usefull in situations where ftp is your only option.

It took me a while to figure it out, so I hope this will save someone else a lot of time :-)

The following assumes that the image is uploaded from a form with a filefield called 'gfx'. I have left out all error checking to keep it simple, so remember to modify the code, to suit your needs.

<?php
$new_width
= 100;
$new_height = 200;
$tmp_image=imagecreatefromjpeg($_FILES['gfx']['tmp_name']);
$width = imagesx($tmp_image);
$height = imagesy($tmp_image);
$new_image = imagecreatetruecolor($new_width,$new_height);
ImageCopyResized($new_image, $tmp_image,0,0,0,0, $new_width, $new_height, $width, $height);
//Grab new image
ob_start();
ImageJPEG($new_image);
$image_buffer = ob_get_contents();
ob_end_clean();
ImageDestroy($new_image);
//Create temporary file and write to it
$fp = tmpfile();
fwrite($fp, $image_buffer)) {
rewind($fp);
//Upload new image
$conn_id = ftp_connect('ftp.example.tld');
ftp_login($conn_id,'user','pass');
ftp_fput($conn_id,'path/to/new/file.jpg', $fp, FTP_BINARY);
fclose($fp);
?>
r dot duclos at chello dot fr
11-Feb-2005 10:41
Hy, here is a little code for generate a thumbnail, very good quality. Enjoy it !

<?php

function miniature($pict, $dest_pict){
  
  
$handle = @imagecreatefromjpeg($pict);

  
$x=imagesx($handle);
  
$y=imagesy($handle);
                                                  
       if(
$x > $y){                               
              
$max = $x;                         
              
$min = $y;                         
       }                                         
       if(
$x <= $y){                               
              
$max = $y;                         
              
$min = $x;                         
       }                                       

//$size_in_pixel : Size max of the label in pixel.  The size of the picture being
//proportional to the original, this value define maximum size
//of largest side with dimensions of the picture. Sorry for my english !

//Here $size_in_pixel = 100 for a thumbnail.
      
$size_in_pixel = '100';

      
$rate = $max/$size_in_pixel;
      
$final_x = $x/$rate;
      
$final_y = $y/$rate;

       if(
$final_x > $x) {
              
$final_x = $x;
              
$final_y = $y;
       }

      
$final_x = ceil($final_x);
      
$final_y = ceil($final_y);

      
$black_picture = imageCreatetruecolor($final_x,$final_y);
      
imagefill($black_picture,0,0,imagecolorallocate($black_picture, 255, 255, 255));
      
imagecopyresampled($black_picture, $handle, 0, 0, 0, 0,$final_x, $final_y, $x, $y);

       if(!@
imagejpeg($black_picture,$dest_pict.'/mini_'.$pict, $size_in_pixel))
      
imagestring($black_picture, 1, $final_x-4, $final_y-8, ".", imagecolorallocate($black_picture,0,0,0));
                      
      
//The number is the quality of the result picture
      
imagejpeg($black_picture,'', '100');
      
imagedestroy($handle);
      
imagedestroy($black_picture);
   }
  
$pict = "PICT7024.jpg";
$dest_pict = "D:/Program Files/EasyPHP1-7/www/test";
miniature($pict, $dest_pict);

?>
arjini at gmail dot com
13-Sep-2004 07:20
Scenario:
   When pointing your browser directly at a script outputting an image, it displays without problem, but when using it in another page via html (i.e. : img src="x.php?yada=yada" ), you get a broken image.

Reason:
   *Any* extra data sent along with the image will cause it to not display on other pages. Extra data may include, whitespace characters (check the begginings and ends of your files), or a call to session_start(), which is what got me.

Summary:
   If you're going to send an image DONT START A SESSION in the script that is outputting the image, and make sure that the PHP delimiters are the first and last things in your file.
10-Sep-2004 11:40
For best results, use only loss-less file formats (such as PNG) for storing images or image parts that you later intend to output with this function.
arjini at gmail dot com
08-Sep-2004 09:48
Converting a directory of PNG images into jpegs is as easy as:

<?php
   $d
= dir('./');
   while(
false !== ($e = $d->read())){
       if(
strpos($e,'.png')){
          
$r = imagecreatefrompng('./'.$e);
          
imagejpeg($r,str_replace('.png','.jpg',$e),75);
       }
   }
?>

Don't let anybody convince you otherwise. Put that in the folder that the images are in and run it. I tried for 2 hours to get photoshop to do it, to no avail. PHP to the rescue!
Olav Alexander Mjelde
07-Jul-2004 08:31
Note to steve:
yes, this is true.. I simply forgot to think about that issue with the clear text to the script..

I think the easiest way to "fix" it, would be to replace the @ in the string with something which cant be used in an email adress..

Then the script would do a replace of excisting of that character..

abc@123.com would then be abc*123.com, which the script would parse back into abc@123.com
Steve
27-Jun-2004 09:14
Regarding Olav's attempt at avoiding spambots, the code will produce a string of code like requests.php?string=<email_address>, and most spambots will parse that email address right out.  You should either create static php scripts to output specific addresses, or do something like save a temporary file on the server with the address you want, and either pass the filename to the makeimage script or have the script open a specific file to check.  If you put the address anywhere on the page the spambot will parse it out, including a tag like href="mailto:xxx".  That's why people use forms to send email now.
Kokesh
26-Jun-2004 12:42
Here is the simple, but powerful script for creating thumbnails on the fly.
You can include the script
directly to www page - just put it in <img src= tag.
with width 150pix.
This resizer respects the ASPECT RATIO.
Here is the script:
<?php
// Use it this way: resize.php?pic=imageurl&width=width_in_pixels
// kokesh@kokeshnet.com 2004
  
header("Content-type: image/jpeg");
  
$im    = imagecreatefromjpeg($pic);
  
$orange = imagecolorallocate($im, 220, 210, 60);
  
$px    = (imagesx($im) - 7.5 * strlen($string)) / 2;

  
$old_x=imageSX($im);
  
$old_y=imageSY($im);

  
$new_w=(int)($width);
   if ((
$new_w<=0) or ($new_w>$old_x)) {
    
$new_w=$old_x;
   }

  
$new_h=($old_x*($new_w/$old_x));

   if (
$old_x > $old_y) {
      
$thumb_w=$new_w;
      
$thumb_h=$old_y*($new_h/$old_x);

   }
   if (
$old_x < $old_y) {
      
$thumb_w=$old_x*($new_w/$old_y);
      
$thumb_h=$new_h;
   }
   if (
$old_x == $old_y) {
      
$thumb_w=$new_w;
      
$thumb_h=$new_h;
   }
    
$thumb=ImageCreateTrueColor($thumb_w,$thumb_h);
    
imagecopyresized($thumb,$im,0,0,0,0,$thumb_w,$thumb_h,$old_x,$old_y);

  
imagejpeg($thumb,"",90);
  
imagedestroy($thumb);
?>
rich @ richud dot com
25-Jun-2004 04:49
'quality' must be a whole number however if a mixed number is given it only uses whole part, e.g. a given value of 90.987 results in 90 being used.
Tom Davis
08-Jun-2004 06:49
I came across a problem where Internet Explorer refused to cache some dynamically created images. To get round this, send out a Last-Modified header.

Eg:

<?php

header
('Last-Modified: '.gmdate('D, d M Y H:i:s', $timestamp).' GMT');
header('Content-Type: image/jpeg');
imagejpeg($photo);

?>
26-May-2004 02:42
A word of warning when outputting images to the browser...

Make sure there is no extra spaces around the <?php ?> tags, in the file you are editing, and also any included files.

I began to think there was a bug in GD or something, and I checked the file I was working on, but forgot about the includes...

Hours gone..
stick [at] geek [dot] hu
24-May-2004 07:08
Just a note to Olav Alexander Mjelde's code: don't forget to put an
imagedestroy($im);
at the end of it or you can run into memory problems.
jannehonkonen at hotmail dot com
05-May-2004 01:44
I had problem wanting to insert stealth - copyrights into images. I could have done this easily with fopen and such, but I still wanted to use imagejpeg(); and it's quality feature. Well this is one kind of solution what I discovered, and seems to work fine.

--code--
$filename = "http://www.domain.com/something.jpg";
$im = imagecreatefromjpeg($filename);
imagejpeg($im,$ModImg,65);
$ModImg .= "This is the text added after EOF of the jpeg";
echo $ModImg;
--code--

As imagejpeg(); inserts imagedata into $ModImg, it does not show the image, but it seems to send headers in that point, so header(); is not needed before echoing variable. Text is viewable with Hex-editors etc.
Olav Alexander Mjelde
07-Apr-2004 09:24
Some people have never heard of spambots, searching the net for email adresses.
How do you avoid this?
Some people write emails like: olav-x AT volvo-power.net (mine btw),
but this will confuse "stupid" users.
The optimal sollution is to have an image with your email adress on.

* When using this function,
you have to put it in a non-html php file..
eg. I put it in a makeimage.php file.
so, how do you display it?

In your users.php, put this:

echo "<b>Email:</b>&nbsp;
       <img src=\"/sql/phpPictures/makeimage.php
         ?string={$row['email']}\">";

Below is the makeimage.php (working example)

<?php
header
("Content-type: image/jpg");
if (!isset(
$string))
  { 
  
$string = "Missing data";
  }

$font  = 4;
$width  = ImageFontWidth($font) * strlen($string);
$height = ImageFontHeight($font);
          
$im = @imagecreate ($width,$height);
//white background
$background_color = imagecolorallocate
                
($im, 255, 255, 255);
//black text
$text_color = imagecolorallocate ($im, 0, 0,0);
imagestring ($im, $font, 0, 0$string, $text_color);

imagejpeg ($im);
?>

Enjoy..
php at andy-pearce dot com
20-Feb-2004 04:42
This might be too obvious, but perhaps worth pointing out. If you want to simply serve images without altering them, it's presumably more efficient to use something like the following:

<?php
  
// Normally $filename would depend on $_GET, etc.
  
$filename = '/photoalbum/images/test.jpg';
  
header('Content-type: image/jpeg');
  
header('Content-transfer-encoding: binary');
  
header('Content-length: '.filesize($filename));
  
readfile($filename);
?>

That way you avoid the overhead of reading and parsing the image, you simply send it directly to the browser.

This is particularly useful if you're using PHP to implement access controls, because it allows you to redirect files from areas of the filesystem browsers can't normally access (although the filename should always come from your script if possible, and not from a URL field, to prevent subverting it with URLs such as image.php?../../../etc/passwd).
gzink at zinkconsulting dot com
01-Jan-2004 07:17
Don't forget that JPEG compression has artifacts! And they're not all really obvious. The PHP JPEG compression is pretty decent, but it seems to generally:

-Lighten the image overall, by a reasonable amount (never seen this before, but it will drive graphic designers crazy, you might want to darken the image before compressing it)
-Reduce saturation, especially with images with lots of points of different color within a few pixels of each other (this is a documented feature of JPEG)
-Seriously mess with blue colors, which is common to all JPEG but really annoying in some situations with blue and black or other detailed blue parts

You might want to consider using imagepng() and outputting a PNG image instead of a JPEG if any of the above affect you, or your image is not very photo-like. Sometimes I have an algorithm compare JPEG to PNG for an image and send the smaller version to the user.

Also, when using imagepng(), you should use imageinterlace() before it 95% of the time. Interlaced JPEGs load progressively, improving in quality as the image loads, so users on slower connections see the whole image at low quality. All this happens without affecting the file size (actually, sometimes the file size is smaller!) or final quality.

Hope this helps a few people out. It's not all that obvious without lots of playing around.

-Galen
http://zinkconsulting.com/
chris AT NOSPAM sketchdiary DOT com
25-Sep-2003 07:20
Just a reminder, if you're passing a string of text via GET, you should rawurlencode() or urlencode() them.  Some older browsers (such as Netscape 4.x) have issues regarding spaces in the URL.

NS 4 shows a broken image:
<image src="newimage.php?text=Show me the text!">

Makes all browsers happy:
<image src="newimage.php?text=<? echo urlencode('Show me the text!'); ?>">

Better to be safe than sorry...
irishcybernerd at email dot com
30-May-2003 01:33
Rather than using the temporary file, as described above, you can buffer the output stream. Someone else showed me this, and it seems to work very nicely.

   //Start buffering the output stream
   ob_start();

   // output the image as a file to the output stream
   Imagejpeg($im);
  
   //Read the output buffer
   $buffer = ob_get_contents();

   //clear the buffer
   ob_end_clean();

   //use $buffer as you wish...
jt at tsw dot org dot uk
25-Feb-2003 11:39
I've just read all this AFTER solving the problem in my own little way. (this is re dumping the image into a string)

Im not actually saving the file to a database, but I'm passing it over XML:RPC so I have the constraint that I cant just dump it to browser, and also its not binary safe.. my solution does not involve ob_start(); which might arguably be the more elgant solution. I didnt see my solution listed, so I thought I aught to post it to add to the wealth of knowledge:

[apologies if this is incorrect, im snipping from a large bit of irrelevent XML:RPC catching stuff]

$tmpfname = tempnam ("/tmp", "FOO");      // Generate the temp file

Imagejpeg($im,$tmpfname);                        // save me image to the file

$temp = fopen($tmpfname,"rb");                  // <- Open the file for reading binary
  
$buffer = fread($temp,filesize($tmpfname));  // get that data into the buffer
fclose($temp);                                            // close the file
unlink($tmpfname);                                    // finished with the file, discard

$out = base64_encode($buffer);                  // encode it (not nessicary if you are using some kind of binary safe function with the info)

and of course on the other end of whatever your doing,

[ some function to get $in ]

header("Content-type: image/jpeg");
$in = base64_decode($buffer);          // get the binary data back
echo $in;

This should work with things like Imagepng

Hope that helps anyone out.
crazyted at crazyted dot com
20-Feb-2003 01:51
In regards to adding images (or any other binary file) to a database, unless you absolutely *have* to, a MUCH better solution is to simply save the file you create to a directory and update your database with a URL to this file.

When I first started DB development I was hung up with BLOBs and how to make them effectively work with PHP but realized that they can severely impact performance and you also limit what you can do with those files once they're inside the DB.

If you can avoid using BLOBs, and most people can, then by all means just create a look-up table for your file urls and save them to a directory to store the files. File access and scalability will be greatly increased in most cases.
dominik at deobald dot org
26-Dec-2002 11:27
About dwards's note: If you choose to send an image to the user directly and don't want to have "strange characters", you have to set the mime-type of the result the user is going to receive:

header('Content-Type: image/jpeg');
imagejpeg($img);
dward at outeru dot comewithnospam
20-Jul-2002 08:57
It took me quite a while to figure out how to output dynamic images along with html with my php scripts.

I may be dim but I'm sure I'm not the only one. So here it is if you need it.

Instead of sending the image directly to the browser, which ends up looking like a bunch of garbage to most users, send an IMG tag with the SRC attribute set to your PHP script that creates the image.

echo '<IMG SRC="makeimg.php?args=YourMakeImgArgs">';
dklein at gmx dot de
12-Dec-2001 12:52
Looks like any specified resolution settings in a JPEG file get lost when using imageJPEG() function in a script.
I had a high resolution JPEG which i added text to with imagestringup() so my customer can print the emailed JPEG as a filled form, but printing both Graphics from Photoshop revealed that any JPEG created is downsampled to 72 dpi, while width and height is kept.
(72 dpi is the standard web resolution)
Nothing to wonder about, but maybe if you read this you dont need to scratch your head :)
pingling at idea dot net dot pl
23-Oct-2001 07:27
As the GD 1.8.4 manual says, the quality should be a value in the range 0-95. And this seems to be true - setting it to 100 doesn't change the default quality.
godehardt at hotmail dot com
04-Jul-2001 03:28
If you call imagecreatefromjpeg and load a jpeg with 75% quality and output it with imagejpeg u can specify the new quality for e.g. 90% and u can increase quality, but output will look like 75% quality picture with the only difference that the new pic is bigger.

So u should check the source quality before u alter output quality. In most cases a quality of 75% is sufficient. For previews i use 50%.

But i make a check if source quality is lower than my personal output quality, i will not chance source quality !

Hope that helps your Webserver and keeps the traffic low :-)
fuxun at sina dot com
15-Jul-2000 07:03
For example:
<?
Header
("Content-type: image/jpeg");
$im = imagecreatefromjpeg("./test.jpg");
Imagejpeg($im,'',20);
ImageDestroy($im);
?>
the jpeg quality from 0 to 100