<?php
/*      ThumbFly 2.0 - by kailey lampert ([email protected], trepmal.com)

        to include your on-the-fly thumbnail do this:
        <img src="<?php echo thumbfly( array( 'src'=>'image.jpg' , 'w' => 250 , 'clean' => true ) ); ?>" />

        free to use & modify, you could probably make it better anyway - in fact, if you do, let me know!

        params (array):
                src = relative/server path to image (required)
                w       = desired width (optional, default = null)
                h       = desired height (optional, default = null)
                name = name of thumbnail (optional, default = src)
                clean = boolean (optional, default = false) if true, remakes thumbs with same name
                warn = boolean (optional, default = false) if true, creates a 'brkn img' image where it can't create thumbnail

                (width & height: if one is defined - image will be scaled, if neither - height & width will be halved)                  */

function thumbfly( $params ) {
        $defaults = array('src' => null, 'w' => null, 'h' => null, 'name' => null, 'clean' => false, 'warn' => false);
        $params = array_merge($defaults, $params);
        extract($params); //get $src, $w, $h, $name, $clean, $warn
        $w  = isset($w) ? $w : false;
        $h = isset($h) ? $h : false; 

        $tmpdir = 'tmp-tf/'; if (!is_dir($tmpdir)) mkdir($tmpdir);
        $newname = (isset($name) ? $name : $src);
        $subdir = (dirname($newname)) ? dirname($newname) : '' ;
        if (!is_dir($tmpdir.$subdir)) mkdir($tmpdir.$subdir);
        $newname = $tmpdir.$newname;
        $type = @exif_imagetype($src);

        if($warn) $clean = false; if($clean) { if (is_file($newname)) unlink($newname); }

        $ok_types = array('1','2','3'); // not perfect, but what is?
        if (!isset($src) || !is_file($src) || !in_array($type,$ok_types) || $warn ) : //unusable src

                if              ( !$w && !$h ) { $w = 135;      $h = 45; } // if no width or height given, use defaults
                else if ( !$w && $h )  { $w = $h; } // if 1 dimension given, make it square
                else if ( !$h && $w )  { $h = $w; } // if 1 dimension given, make it square
                $img = imagecreatetruecolor($w, $h);
                $text_color = imagecolorallocate($img, 200, 200, 200);
                imagestring($img, 2, 5, 10, 'brkn img', $text_color);
                if ($warn)      { imagejpeg($img,$newname); }
                else            { $newname = ''; }
                imagedestroy($img);

        elseif (is_file($newname)) : // if tmp img exists..
                /* nothing happening... */
        else :  //src is real and thumb isn't cached... let's start resizing!

                list($ow, $oh) = getimagesize($src); //get dimensions of src img
                $or = $ow/$oh; //original ratio

                if              ( !$w && !$h ) { $w = $ow*(0.5);        $h = $oh*(0.5); } // if no width or height given - change defaults here!
                else if ( !$w && $h )  { $w = ($h*$or); } //only height? scale
                else if ( !$h && $w )  { $h = ($w/$or); } //only width? scale
                $r = $w/$h; //here to prevent division by zero

                $image_thumb = imagecreatetruecolor($w,$h); //create blank canvas in defined proportions

                $modwidth = $ow;        $modheight = $oh; //scaled size to work from
                $off_w = 0;                     $off_h = 0; //offsets
                if ($r > $or) :                         //if new is more landscape-y than original
                        $modheight = $ow/$r;    //slice off some of top & bottom
                        $off_h = ($oh-$modheight)/2; //get .5 the diff for centering (even slicing)
                elseif ($ratio < $or) :         //and reverse...
                        $modwidth = $oh*$r;
                        $off_w = ($ow-$modwidth)/2;
                endif;

                switch ($type) {
                        case 1: /*gif*/
                                $image_original = imagecreatefromgif($src);
                                $trns_ind = imagecolortransparent($image_original);
                                if ($trns_ind >= 0) {
                                        $trns_color    = imagecolorsforindex($image_original,  $trns_ind);
                                        $trns_ind    = imagecolorallocate($image_thumb, $trns_color['red'], $trns_color['green'], $trns_color['blue']);
                                        imagefill($image_thumb, 0, 0, $trns_ind);
                                        imagecolortransparent($image_thumb, $trns_ind);
                                }
                                imagecopyresampled($image_thumb, $image_original, '0', '0', $off_w, $off_h, $w, $h, $modwidth, $modheight);
                                $the_thumb .= '.gif'; $thumb_loc .= '.gif';
                                imagegif($image_thumb, $newname);
                          break;
                        case 2: /*jpg*/
                                $image_original = imagecreatefromjpeg($src);
                                imagecopyresampled($image_thumb, $image_original, '0', '0', $off_w, $off_h, $w, $h, $modwidth, $modheight);
                                imagejpeg($image_thumb, $newname, 100);
                          break;
                        case 3: /*png*/
                                $image_original = imagecreatefrompng($src);
                                imagealphablending( $image_thumb, false );
                                imagesavealpha( $image_thumb, true );
                                imagecopyresampled($image_thumb, $image_original, '0', '0', $off_w, $off_h, $w, $h, $modwidth, $modheight);
                                imagepng($image_thumb, $newname);
                          break;
                }//end switch
                imagedestroy($image_thumb);
        endif;
        return $newname;
}// end function
?>

http://trepmal.com/scripts/thumbfly-on-the-fly-thumbnails/

ThumbFly: On-the-fly thumbnails

PHP