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Need help fixing (or finding) PHP-based thumbnail image generating script

Posted on 2009-05-18
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Last Modified: 2013-12-13
I'm having a really hard time getting the attached PHP-based thumbnail image generating script to work on my windows-based shared hosting account.  

The errors that I'm getting when I try to apply the createthumb() function -- using 100% valid image resources --- are as follows:

Notice: Undefined offset: 1 in D:\Inetpub\antiqueplace\webauction\upload\thumbnail_generator.php on line 92

Notice: Undefined variable: tmparr
Notice: Undefined variable: src_img
Warning: imagesx(): supplied argument is not a valid Image resource
Warning: imagesy(): supplied argument is not a valid Image resource
Notice: Undefined variable: src_img
Warning: imagecopyresampled(): supplied argument is not a valid Image resource
Warning: imagedestroy(): supplied argument is not a valid Image resource

(etc..)

It's confusing because I've gotten this script to work without any problems several times already (on the same shared hosting environment) .. yet for some reason I can't get the script to work properly in this case. Why is this script failing? How can I fix it?

If anyone knows of a better way for me to create thumbnail images using PHP ... I'd be open to replacing what I've got with it.  

Thanks,
- Yvan


<?php 
$imagefolder='.';
$thumbsfolder='.';
$pics=directory($imagefolder,"jpg,JPG,JPEG,jpeg,png,PNG");
$pics=ditchtn($pics,"tn_");
if ($pics[0]!="")
{
	foreach ($pics as $p)
	{
		createthumb($p,"tn_".$p,150,150);
	}
}
 
/*
	Function ditchtn($arr,$thumbname)
	filters out thumbnails
*/
function ditchtn($arr,$thumbname)
{
	foreach ($arr as $item)
	{
		if (!preg_match("/^".$thumbname."/",$item)){$tmparr[]=$item;}
	}
	return $tmparr;
}
 
/*
	Function createthumb($name,$filename,$new_w,$new_h)
	creates a resized image
	variables:
	$name		Original filename
	$filename	Filename of the resized image
	$new_w		width of resized image
	$new_h		height of resized image
*/	
function createthumb($name,$filename,$new_w,$new_h)
{
	$system=explode(".",$name);
	if (preg_match("/jpg|jpeg/",$system[1])){$src_img=imagecreatefromjpeg($name);}
	if (preg_match("/png/",$system[1])){$src_img=imagecreatefrompng($name);}
	$old_x=imageSX($src_img);
	$old_y=imageSY($src_img);
	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;
	}
	$dst_img=ImageCreateTrueColor($thumb_w,$thumb_h);
	imagecopyresampled($dst_img,$src_img,0,0,0,0,$thumb_w,$thumb_h,$old_x,$old_y); 
	if (preg_match("/png/",$system[1]))
	{
		imagepng($dst_img,$filename); 
	} else {
		imagejpeg($dst_img,$filename); 
	}
	imagedestroy($dst_img); 
	imagedestroy($src_img); 
}
 
/*
        Function directory($directory,$filters)
        reads the content of $directory, takes the files that apply to $filter 
		and returns an array of the filenames.
        You can specify which files to read, for example
        $files = directory(".","jpg,gif");
                gets all jpg and gif files in this directory.
        $files = directory(".","all");
                gets all files.
*/
function directory($dir,$filters)
{
	$handle=opendir($dir);
	$files=array();
	if ($filters == "all"){while(($file = readdir($handle))!==false){$files[] = $file;}}
	if ($filters != "all")
	{
		$filters=explode(",",$filters);
		while (($file = readdir($handle))!==false)
		{
			for ($f=0;$f<sizeof($filters);$f++):
				$system=explode(".",$file);
				if ($system[1] == $filters[$f]){$files[] = $file;}
			endfor;
		}
	}
	closedir($handle);
	return $files;
}
?>

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Question by:egoselfaxis
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6 Comments
 
LVL 111

Expert Comment

by:Ray Paseur
ID: 24416307
This is the code I use for "index.php" in photo directories.  It makes thumbnails if they do not already exist.  Please look it over and post back here if you have any questions.

Best regards, ~Ray
<?php // RAY_photo_directory.php
error_reporting(E_ALL);
 
// ALLOWABLE WIDTH AND HEIGHT
DEFINE('W', 360);
DEFINE('H', 360);
 
// THUMBNAIL PREFIX
DEFINE('T', "tn_");
 
// GET THE NAMES OF ALL THE FILES
$dir = scandir(getcwd());
 
// WINNOW THE CHAFF
foreach ($dir as $ptr => $jpg)
{
    if (!eregi(".jpg$", $jpg))
    {
        unset($dir[$ptr]);
    }
}
 
// MAKE THUMBNAILS
$prefix_regex = '^' . T;
foreach ($dir as $ptr => $jpg)
{
// IF THIS IS A THUMBNAIL, SKIP IT
    if (eregi("$prefix_regex", $jpg))
    {
        unset ($dir[$ptr]);
        continue;
    }
 
// IF WE ALREADY HAVE A THUMBNAIL
    $thumb = T . $jpg;
    if (!in_array($thumb, $dir))
    {
        $imageblob = create_right_size_image($jpg);
        imagejpeg($imageblob, $thumb);
    }
}
 
// WE HAVE ADDED TO THE DIRECTORY - REGET THE NAMES OF ALL THE FILES
$dir = scandir(getcwd());
 
// WINNOW THE CHAFF - KEEP ONLY THE ORIGINAL JPG FILE NAMES
$prefix_regex = '^' . T;
foreach ($dir as $ptr => $jpg)
{
    if ( !eregi(".jpg$", $jpg) || eregi("$prefix_regex", $jpg) )
    {
        unset($dir[$ptr]);
    }
}
 
// DISPLAY THE THUMBNAIL LINKS
foreach ($dir as $ptr => $jpg)
{
    $thumb = T . $jpg;
    echo "<br clear=\"all\" /><a href=\"$jpg\"><img src=\"$thumb\"></a>\n";
}
 
// DONE
die();
 
 
 
 
// LOCAL FUNCTIONS
 
// A FUNCTION TO DETERMINE IF GD IS AT LEVEL 2 OR MORE
function get_gd_info($display=FALSE)
{
 
// IS GD INSTALLED AT ALL?
   if (!function_exists("gd_info"))
   {
      if ($display) echo "<br/>GD NOT INSTALLED\n";
      return FALSE;
   }
 
// IF GD IS INSTALLED GET DETAILS
   $gd = gd_info();
 
// IF DISPLAY IS REQUESTED, PRINT DETAILS
   if ($display)
   {
      echo "<br/>GD DETAILS:\n";
      foreach ($gd as $key => $value)
      {
         if ($value === TRUE)  $value = 'YES';
         if ($value === FALSE) $value = 'NO';
         echo "<br/>$key = $value \n";
      }
   }
 
// RETURN THE VERSION NUMBER
   $gd_version = ereg_replace('[^0-9\.]', '', $gd["GD Version"]);;
   return $gd_version;
}
 
 
// A FUNCTION TO MAKE AN IMAGE INTO THE RIGHT WIDTH FOR PAGE DISPLAY
// WILL WORK IF GD2 NOT INSTALLED, BUT WILL MAKE BETTER IMAGES WITH GD2
// INPUT IS THE IMAGE FILE NAME, OUTPUT IS AN IMAGE RESOURCE
function create_right_size_image($image, $width=W, $height=H)
{
// IS GD HERE?
   $gdv = get_gd_info();
   if (!$gdv) return FALSE;
 
// GET AN IMAGE THING
   $source = imagecreatefromjpeg("$image");
 
// GET THE X AND Y DIMENSIONS
   $imageX = imagesx($source);
   $imageY = imagesy($source);
 
// IF NO RESIZING IS NEEDED
   if ( ($imageX <= $width) && ($imageY <= $height) )
   {
      return $source;
   }
 
// IF THE WIDTH IS TOO GREAT - MUST RESIZE
   if ($imageX > $width)
   {
      $tnailX = $width;
      $tnailY = (int) (($tnailX * $imageY) / $imageX );
   }
 
// IF THE HEIGHT IS TOO GREAT - MUST RESIZE
   if ($imageY > $height)
   {
      $tnailY = $height;
      $tnailX = (int) (($tnailY * $imageX) / $imageY );
   }
 
// WHICH FUNCTIONS CAN RESIZE / RESAMPLE THE IMAGE?
   if ($gdv >= 2)
   {
// IF GD IS AT LEVEL 2 OR ABOVE
      $target = imagecreatetruecolor($tnailX, $tnailY);
      imagecopyresampled ($target, $source, 0, 0, 0, 0, $tnailX, $tnailY, $imageX, $imageY);
   } else
   {
// IF GD IS AT A LOWER REVISION LEVEL
      $target = imagecreate($tnailX, $tnailY);
      imagecopyresized   ($target, $source, 0, 0, 0, 0, $tnailX, $tnailY, $imageX, $imageY);
   }
   return $target ;
}

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Author Comment

by:egoselfaxis
ID: 24421303
Is there any possibility of getting something a bit simpler -- perhaps something that handles the thumbnail creation for a single JPEG image?  
0
 
LVL 111

Accepted Solution

by:
Ray Paseur earned 2000 total points
ID: 24422793
Yes.  Please read the code posted here.  That is EXACTLY what the function create_right_size_image does.
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LVL 111

Expert Comment

by:Ray Paseur
ID: 24422815
The calling sequence for that function is on lines 38 and 39.

HTH, ~Ray
        $imageblob = create_right_size_image($jpg);
        imagejpeg($imageblob, $thumb);

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Author Comment

by:egoselfaxis
ID: 24426769
Thanks Ray!

- Yvan
0
 
LVL 111

Expert Comment

by:Ray Paseur
ID: 24426815
Thanks for the points, Yvan - it's a great question! ~Ray
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