class.upload.php is a powerful and mature PHP class to manage uploaded files, and manipulate images in many ways. The script is available under a GPL license.
However, starting wit hthe code that you have, you can use image_cropwith negative values in order to add "space" on the sides of the picture if the original picture is less than 200px wide.
So if the picture's width (or height) is less than 200px, you keep it as is, and calculate the space you need to add, and set a negative cropping value. If the image is 200px or wider, then you simply resize it using image_ratio_crop or image_ratio_fill.Reply
However, starting wit hthe code that you have, you can use image_cropwith negative values in order to add "space" on the sides of the picture if the original picture is less than 200px wide.
So if the picture's width (or height) is less than 200px, you keep it as is, and calculate the space you need to add, and set a negative cropping value. If the image is 200px or wider, then you simply resize it using image_ratio_crop or image_ratio_fill.