NYCPHP Meetup

[David Krings]

Jonathan Wagener wrote:
> Hi, I would like to know how I can make phpthumb work, I don't really
> understand how it works. How do I make it create thumbnails?
> 

Hi!

I can't answer your question, but I know about an alternative. You can use 
exif to read out the thumbnail from jpegs and then display that. The thumbnail 
is stored as a string, but PHP has functions for that. I put this together 
with a lot of help from the smart people from NYPHP.

This is the piece of code that displays the thumbnail
       // Show thumbnail
       $exifthumbnail = exif_thumbnail($totalpath, $exifwidth, $exifheight, 
$exiftype);
       if ($exifthumbnail !== FALSE) {
             echo "<tr><td>Thumbnail image</td><td><img class=\"centerborder\" ".
                  "src=\"tn.php?degrees=".$rotate."&f=".$totalpath."\">";
             echo "</td></tr>\n";
       } else {
             echo "<tr><td>Thumbnail image</td><td>No thumbnail 
available!</td></tr>\n";
       }

And that is piece of code that makes the thumbnail (reference above as tn.php):
<?php
// =============================================================================
// This script is a helper script to generate a thumbnail image from Exif data
// =============================================================================

if ($_GET['degrees'] == 0) {
    $image = exif_thumbnail($_GET['f'], $width, $height, $type);
    header('Content-type: ' .image_type_to_mime_type($type));
    echo $image;
} else {
    $image = exif_thumbnail($_GET['f'], $width, $height, $type);
    $realimage = imagecreatefromstring($image);
    $rotimage = imagerotate($realimage, $_GET['degrees'], 0);
    header('Content-type: ' .image_type_to_mime_type($type));
    imagejpeg($rotimage);
    // echo $rotimage;
}
?>


$totalpath is the path to the jped image, $degrees is the amount of degrees 
the thumbnail needs to be rotated (the same as the image, I specify the angle 
on image insert/edit, also some cameras have a sensor that stores it in the 
exif info), the $exif.... values are straight from the thumbnail info out of 
the exif header. I display all exif info in a table and show the thumbnail in 
the table cell centered with a border (see class for img tag). The really 
weird thing with this is that the img tag src value is a link to the tn.php 
script. Also a nice example where GET comes to the rescue where POST would be 
awfully complicated.

HTH,

	David