Easily Calculate Image Scaling to Fit or Fill a Destination Box
CJ Image: An Image Scaling Algorithm
One of the most requested functions that my customers seem to ask, is that they want to upload their own images to the website. Technically, it's not difficult, especially if your using a server technology like ColdFusion, php, etc, but from a design perspective, it's a big headache. When designing a website, you create "blocks" (for lack of a better term) that are either going to be used for text or images. You might use an image editing programing like Adobe® Photoshop® to scale and crop the images to make sure they load fast and fit into the block's dimensions. Unfortunately, most of our customers do not have these tools and wind up trying to upload an image that are to large and weren't really designed to fit within our designated "block".
We needed to create a function that would take our customers uploaded image and scale it into these blocks. Not knowing what the customer was going to upload, we had to create something that was dynamic enough to adapt to what ever size the final destination image was going to be and also to the source image the user uploads.