How to find image width and height dynamically and specify height, width attibutes if over certain dimensions?

I display some data on my website and one of the data feed elements is an image.

[title] => Product title
[description] => some description
[image] =>开发者_运维百科 www.some-domain.com/product-image/p12345.jpg

I then display this image using

<img alt="product" src="<?=$data['image']?>" />

Most of the images are 80x80, 120x100 or other less than 150 in width, which perfectly fit in the website template, but some of them are quite large such as 800x600 which distort the layout. I want a control on these types.

I tried to set WIDTH="150", but as the width vary they dont look good. I was thinking If I could set a fixed width to images, say, larger than 250px then I can live with it for now. Any ideas how to achieve this?

Thanks

I have used getimagesize() for exactly this.

$size = getimagesize( "http://www.some-domain.com/product-image/p12345.jpg" );
$width = $size[0];
$height = $size[1];