PHP GD library resize photo

Question

I am attempting to create thumbnails of photos using PHP's GD library.

Here are the steps I am taking.

1. Create GD Image resource.
2. Get height and width of image
3. create a blank gd image resource at 100 pixels high by appropriate width
4. copy resource image to blank gd image resource and save both images

Here is my code:

private function getExtension($filename) {
    $position=strrpos($filename, '.');
    $extension = strtolower(substr($filename, $position+1));
    if ($extension == "jpg") {
        $extension = "jpeg";
    }

    return $extension;
}

public function saveImage($parameters) {
    $extension=$this->getExtension($parameters['filename']);
    $createImageFunc="imagecreatefrom".$extension;
    $imgResource=$createImageFunc(SITE_PATH."tmp/{$parameters['filename']}");
    $width=imagesx($imgResource);
    $height=imagesy($imgResource);
    $ratio=$height/$width;
    $thumbnail=imagecreatetruecolor(100, 100*$ratio);

    imagecopyresized($thumbnail, $imgResource, 0, 0, 0, 0, 100*$ratio, 100, $width, $height);

    $imgResult=imagejpeg($imgResource, SITE_PATH."images/{$parameters['galleryName']}/{$parameters['filename']}");
    $thumbResult=imagejpeg($thumbnail, SITE_PATH."images/{$parameters['galleryName']}/thumbnails/{$parameters['filename']}");

}

The images are saving, but the copy is not working, there is empty black space in the thumbnail picture.

This is the original Image:

This is the image saved again with gd:

This is the thumbnail:

I've like quadruple checked imagecopyresize and from what I understand of it all the values in the code should be correct.

Here is what php.net has for the values:

bool imagecopyresized ( resource $dst_image , resource $src_image , int $dst_x , int $dst_y , int $src_x , int $src_y , int $dst_w , int $dst_h , int $src_w , int $src_h )

Any one got any ideas?

Answer 1

Take a look at this: PHP/GD Imagestyle
You can easily create thumbnails or everything you want

// create a thumbnail
$thumb = imagestyle($image,'autosize:100 100');
// resize the image # resize:200 0; means width=200 height=auto
$resized = imagestyle($image,'resize:200 0;');
// crop it # left=0, top=50, width=200, height=200
$cropped = imagestyle($image,'crop:0 50 200 200;');
// and more

Answer 2

Working with PHP/GD can be tedious, so I wrote a library to make things much easier: SimpleImage

With SimpleImage, you can create a thumbnail in two simple lines:

// Load image from image.jpg
$image = new \claviska\SimpleImage('image.jpg');

// Create a 100x100 thumbnail, convert to PNG, and save to thumb.png
$image->thumbnail(100, 100)->toFile('thumb.png', 'image/png');

If you're still bent on doing it manually, check your imagecopyresized parameters. Why is the width being multiplied by $ratio ?