Problem with Thumbnail Creation

tmiddlet

Hi all.

I am using the following code to create a thumbnail from a jpeg image.

I have used this in two different ISP's with different versions of php.

On the first ISP, after running phpinfo() they have the following versions:
PHP Version 4.2.2
GD 1.6.2 or higher
On this host the thumbnail converison works fine.

On the second ISP, the same code creates thumbnails that look sepia tone.
phpinfo() details are:
PHP Version 4.3.4
GD - bundled (2.0.15 compatible)

I have tried imagecopyresampled as well but to no avail.

THanks for your help.

function thumbnail_convert($image_path, $thumb_path, $image_name, $thumb_width)
{
echo "<b>$image_path/$image_name</b>";
$src_img = imagecreatefromjpeg("$image_path/$image_name");
$origw=imagesx($src_img);
$origh=imagesy($src_img);
$new_w = $origw / 5;
$new_h = $origh / 5;
$dst_img = imagecreate($new_w,$new_h);
// imagecopyresampled($dst_img,$src_img,0,0,0,0,$new_w,$new_h,imagesx($src_img),imagesy($src_img));

imagecopyresized($dst_img,$src_img,0,0,0,0,$new_w,$new_h,imagesx($src_img),imagesy($src_img)); 

imagejpeg($dst_img, "$thumb_path/$image_name"); 
return true;

}

drawmack

the only thing I can think that it may be is that the new height and width may be floating point numbers and that might have a ngative impact on the gd engine.

or if the new server is a windows machine then your / in the path should be a \

here is the code fixed to prevent floating point height and width values:

<?php
function thumbnail_convert($image_path, $thumb_path, $image_name, $thumb_width) { 
    echo "<b>$image_path/$image_name</b>"; 
    $src_img = imagecreatefromjpeg("$image_path/$image_name"); 
    $origw=imagesx($src_img); 
    $origh=imagesy($src_img); 
    $new_w = intval($origw / 5); 
    $new_h = intval($origh / 5); 
    $dst_img = imagecreate($new_w,$new_h); 
    imagecopyresized($dst_img,$src_img,0,0,0,0,$new_w,$new_h,$origw,$origh); 

imagejpeg($dst_img, "$thumb_path/$image_name"); 
return true; 
} //end thumbnail_convert
?>

tmiddlet

Hi.

Thanks for your reply.

I'll give it a go.

Do you think that the different gd version or php verison should make a difference?

It seems it works worst in the new verison.

BTW, both machines are Linux.

jpmoriarty

try doing

ImageCreateTrueColor(...)

instead of

ImageCreate(...)

Weedpacket

Originally posted by jpmoriarty
try doing
ImageCreateTrueColor(...)
instead of
ImageCreate(...)
[/B]

I'd agree with this; when using ImageCreate, gd forces the JPEG image into a 256-colour palette - and it doesn't select the palette very well.

You may also want to switch to imagecopyresampled() instead of imagecopyresized(); the former does a better job of interpolation.

tmiddlet

I used ImageCreateTrueColor and imagecopyresampled and it now works a treat.

Thanks very much to all who replied.

Cheers from Perth,