Create Thumbnail

To generate thumbnail, here is the  simple and easiest way. It will help you in creating thumb for jpg, png and gif images.

/* generateThumb()
 *
 * @param mixed $source Path to source file
 * @param mixed $destination Path to destination file
 * @param mixed $width Thumbnail file width
 * @param mixed $height Thumbnail file height
 * @return bool
 */

function generateThumb($source, $destination, $width = 100, $height = 100){
 
 $ext = strtolower(substr($source, strrpos($source, ".")+1));
 $format = ($ext == 'jpg')?'jpeg':$ext;
 $from_format = "imagecreatefrom".$format;
 $source_image = $from_format ( $source );

 $source_width = imagesx ( $source_image );
 $source_height = imagesy ( $source_image );

 $ratio1 = $source_width/ $width;
 $ratio2 = $source_height / $height;

 if($ratio1 > $ratio2){
  $width = $width;
  $height = $source_height/$ratio1;
 }else{
  $width = $source_width/$ratio2;
  $height = $height;
 }

 $target_image = imagecreatetruecolor($width,$height);
 imagecopyresampled($target_image, $source_image, 0, 0, 0, 0, $width, $height, $source_width, $source_height);
 
 $image_function = "image" . $format;
 return $image_function ( $target_image, $destination, 100 );
 
}

Here is how you use it...

if(generateThumb("images/a.jpg", "images/thumbs/a.jpg", 150, 100)){
    echo "done";
} else {
    echo "failed"; 
}