Resize images with PHP, support PNG, JPG

function resize($newWidth, $targetFile, $originalFile) {    $info = getimagesize($originalFile);    $mime = $info['mime'];    switch ($mime) {            case 'image/jpeg':                    $image_create_func = 'imagecreatefromjpeg';                    $image_save_func = 'imagejpeg';                    $new_image_ext = 'jpg';                    break;            case 'image/png':                    $image_create_func = 'imagecreatefrompng';                    $image_save_func = 'imagepng';                    $new_image_ext = 'png';                    break;            case 'image/gif':                    $image_create_func = 'imagecreatefromgif';                    $image_save_func = 'imagegif';                    $new_image_ext = 'gif';                    break;            default:                     throw new Exception('Unknown image type.');    }    $img = $image_create_func($originalFile);    list($width, $height) = getimagesize($originalFile);    $newHeight = ($height / $width) * $newWidth;    $tmp = imagecreatetruecolor($newWidth, $newHeight);    imagecopyresampled($tmp, $img, 0, 0, 0, 0, $newWidth, $newHeight, $width, $height);    if (file_exists($targetFile)) {            unlink($targetFile);    }    $image_save_func($tmp, "$targetFile.$new_image_ext");}

I've written a class that will do just that and is nice and easy to use. It's called
PHP Image Magician

$magicianObj = new imageLib('racecar.jpg');$magicianObj -> resizeImage(100, 200);$magicianObj -> saveImage('racecar_convertd.png', 100);

It supports Read and Write (including converting) the following formats

• jpg
• png
• gif
• bmp

And can read only

• psd's

Example

// Include PHP Image Magician libraryrequire_once('php_image_magician.php');// Open JPG image$magicianObj = new imageLib('racecar.jpg');// Resize to best fit then crop$magicianObj -> resizeImage(100, 200, 'crop');// Save resized image as a PNG$magicianObj -> saveImage('racecar_small.png');

You can try this. Currently it's assuming the image will always be a jpeg. This will allow you to load a jpeg, png, or gif. I haven't tested but it should work.

function resize($newWidth, $targetFile) {    if (empty($newWidth) || empty($targetFile)) {        return false;    }    $fileHandle = @fopen($this->originalFile, 'r');    //error loading file    if(!$fileHandle) {        return false;    }    $src = imagecreatefromstring(stream_get_contents($fileHandle));    fclose($fileHandle);    //error with loading file as image resource    if(!$src) {        return false;    }    //get image size from $src handle    list($width, $height) = array(imagesx($src), imagesy($src));    $newHeight = ($height / $width) * $newWidth;    $tmp = imagecreatetruecolor($newWidth, $newHeight);    imagecopyresampled($tmp, $src, 0, 0, 0, 0, $newWidth, $newHeight, $width, $height);    //allow transparency for pngs    imagealphablending($tmp, false);    imagesavealpha($tmp, true);    if (file_exists($targetFile)) {        unlink($targetFile);    }    //handle different image types.    //imagepng() uses quality 0-9    switch(strtolower(pathinfo($this->originalFile, PATHINFO_EXTENSION))) {        case 'jpg':        case 'jpeg':            imagejpeg($tmp, $targetFile, 95);            break;        case 'png':            imagepng($tmp, $targetFile, 8.5);            break;        case 'gif':            imagegif($tmp, $targetFile);            break;    }    //destroy image resources    imagedestroy($tmp);    imagedestroy($src);}