[Resolved] Resize image error message

[tomandhannah]

I am (attempting) to use the following code that I got (and altered) from the PHP manual posts at: http://www.php.net/manual/en/function.imagecopyresized.php

<?php

$filename = "/images/lessons/1.JPG";
$maxwidth == "240";
$maxheight == "400";

// Resize an image if it exceeds a predefined size.

  if (is_file($filename)) { /* check if the file is really one */
   $fd = @fopen($filename,"r");
   $image_string = fread($fd,filesize($filename));
   fclose($fd);

   $im = ImageCreateFromString($image_string);
   $currwidth = ImageSX($im);
   $currheight = ImageSY($im);

/* now we have to check if the image
    is higher than wider and larger
    than the defined size, then
    calculte it and resize it proportional */
   if ($currwidth > $currheight && $currwidth > $maxwidth) {
    $percent = ($maxwidth * 100) / $currwidth;
    $nwidth = $maxwidth;
    $nheight = ($percent * $currheight) / 100;
   } elseif ($currwidth < $currheight && $currheight > $maxheight) {
    $percent = ($maxheight * 100) / $currheight;
    $nheight = $maxheight;
    $nwidth = ($percent * $currwidth) / 100;
   }
   $nwidth = intval($nwidth);
   $nheight = intval($nheight);

/* ok. let's create the new smaller image
    with calculated size... */
   $newim = imagecreate ($nwidth, $nheight);

/* ...and put the lager image into the
    smaller one. */
imagecopyresized($newim,$im,0,0,0,0,$nwidth,$nheight,$width,$height);

$add = "x";
$newfilename = "$add$filename";

   unlink($filename); /* we need to delete the file,
                        because we want to replace
                        the original file with the
                        resized one              */

   /* now save to file and clear up the memory  */
   imagepng($newim,$newfilename);
   ImageDestroy($im);
   ImageDestroy($newim);

/* if you want, use the returned HTML-Code
    and insert it into an <img>-tag */
   return "width=\"".$nwidth."\" height=\"".$nheight."\"";
   print "Success!!";
  } else {
   /* if the file wasn't a file return false */
   return false;
   print "Problem";
  }


?>

This should open the image, check and see if it's larger than allowed, resize, and save. Right now, all it does is delete the original file and provide me with the following errors:

Warning: imagecreate(): Invalid image dimensions in /resize.php on line 36

Warning: imagecopyresized(): supplied argument is not a valid Image resource in /resize.php on line 40

Warning: imagepng(): supplied argument is not a valid Image resource in /resize.php on line 51

Warning: imagedestroy(): supplied argument is not a valid Image resource in /resize.php on line 53

Anyone know what the problem is? I have PHP4.3. I downloaded and installed GD today, but my php.ini file does not have a line for GD, only a line for the windows extension for GD. But other than that, the phrase 'gd' doesn't exist anywhere in my php.ini file. Could this be the problem? Does imagecopyresized() require GD?

[The_Chancer]

Comment the lines 52-54 and return the values of nwidth and nheight - see if those are true (your first error) after that then it should work as that is causing all the other errors as far as I can see...

Oh - that and the double == at the start....

[tomandhannah]

Just for clarification: can you tell me exactly what lines of code you're asking me to comment? My line 52 begins with ImageDestroy($im);

I've comment several lines to see what's going on. below is the current script and new error message. The dimensions are correct. I found the issue with why the dimensions weren't passing correctly.

<?php

$path = "/Library/Apache2/htdocs/images/lessons/";
$file = "3.JPG";
$filename = "$path$file";
$maxwidth = "240";
$maxheight = "400";

// Resize an image if it exceeds a predefined size.

  if (is_file($filename)) { /* check if the file is really one */
   $fd = @fopen($filename,"r");
   $image_string = fread($fd,filesize($filename));
   fclose($fd);

   $im = ImageCreateFromString($image_string);
   $currwidth = ImageSX($im);
   $currheight = ImageSY($im);

/* now we have to check if the image
    is higher than wider and larger
    than the defined size, then
    calculte it and resize it proportional */
   if ($currwidth > $currheight && $currwidth > $maxwidth) {
    $percent = ($maxwidth * 100) / $currwidth;
    $nwidth = $maxwidth;
    $nheight = ($percent * $currheight) / 100;
   } elseif ($currwidth < $currheight && $currheight > $maxheight) {
    $percent = ($maxheight * 100) / $currheight;
    $nheight = $maxheight;
    $nwidth = ($percent * $currwidth) / 100;
   }
   $nwidth = intval($nwidth);
   $nheight = intval($nheight);

/* ok. let's create the new smaller image
    with calculated size... */
   $newim = imagecreate ($nwidth, $nheight);

   print "New size: $nwidth x $nheight <BR><BR>";
    print "Old size: $currwidth x $currheight <BR><BR>";

/* ...and put the lager image into the
    smaller one. */
imagecopyresized($newim,$im,0,0,0,0,$nwidth,$nheight,$currwidth,$currheight);

$add = "x";
$newfilename = "$add$file";

   #unlink($filename); /* we need to delete the original file

   /* now save to file and clear up the memory */
   imagepng($newim,$newfilename);
   #ImageDestroy($im);
   #ImageDestroy($newim);

/* if you want, use the returned HTML-Code
    and insert it into an <img>-tag */
   #print "Success!!";
  } else {
   /* if the file wasn't a file return false */
   return false;
   print "Problem";
  }

?>

And the output now is:

New size: 240 x 160 

Old size: 2160 x 1440 


Warning: imagepng(): Unable to open 'x3.JPG' for writing in /Library/Apache2/htdocs/admin/resize.php on line 53
[/HMTL]


Why can imagepng() not open the file?

[tomandhannah]

The problem was I left out the $path in

$add = "a";
$newfilename = "$path$add$file";

Now it works and creates the image, but it looks terrible!

Any suggestions for making the image look better? This image is all dark and grainy. Also, my graphics program couldn't open it, but the browser could.

[The_Chancer]

Use GD2 and imagecreatetruecolor()...

As to graphics prog not opening it... unsure - which app on which OS ?

[tomandhannah]

Ok, it's all good now. Thanks so much for your help. For those of you following this forum, below is the final code that works (with JPEGs)...

The problem with the file only opening in my browser was that I was using imagepng when the file was a jpeg. So, now I'm using imagejpeg and everything's swell.

<?php

$path = "/Library/Apache2/htdocs/images/lessons/";
$file = "5.JPG";
$filename = "$path$file";
$maxwidth = "300";
$maxheight = "500";

// Resize an image if it exceeds a predefined size.

  if (is_file($filename)) { /* check if the file is really one */
   $fd = @fopen($filename,"r");
   $image_string = fread($fd,filesize($filename));
   fclose($fd);

   $im = ImageCreateFromString($image_string);
   $currwidth = ImageSX($im);
   $currheight = ImageSY($im);

/* now we have to check if the image
    is higher than wider and larger
    than the defined size, then
    calculte it and resize it proportional */
   if ($currwidth > $currheight && $currwidth > $maxwidth) {
    $percent = ($maxwidth * 100) / $currwidth;
    $nwidth = $maxwidth;
    $nheight = ($percent * $currheight) / 100;
   } elseif ($currwidth < $currheight && $currheight > $maxheight) {
    $percent = ($maxheight * 100) / $currheight;
    $nheight = $maxheight;
    $nwidth = ($percent * $currwidth) / 100;
   }
   $nwidth = intval($nwidth);
   $nheight = intval($nheight);

/* ok. let's create the new smaller image
    with calculated size... */
   $newim = imagecreatetruecolor ($nwidth, $nheight);

/* ...and put the larger image into the
    smaller one. */
imagecopyresized($newim,$im,0,0,0,0,$nwidth,$nheight,$currwidth,$currheight);

$add = "a";
$newfilename = "$path$add$file";

   unlink($filename); /* we need to delete the original file

   /* now save to file and clear up the memory */
   imagejpeg($newim,$newfilename,80);
   ImageDestroy($im);
   ImageDestroy($newim);

/* if you want, use the returned HTML-Code
    and insert it into an <img>-tag */
   print "Success!!";
  } else {
   /* if the file wasn't a file return false */
   return false;
   print "Problem";
  }

?>