Question

Got a question. I have images hosted on my server. I already know of the method when an image is uploaded to resize it and save, but I have another thought in mind.

1. I was wondering if there is a way to resize when the image is requested from the user. Not when it was uploaded by the user.

So for example a user goes to upload an image and I DO NOT RESIZE it and save another copy of the resized image. Instead, when the image is requested by the user via an ASP.NET img control/tag it would resize the image on the fly to display it and display it via the img tag/control.

Why would I want to do this?

To save on disk space. Most servers have a disk space limit, but not a server processing limit. So I would like to save on disk space and use the processing space instead.

EDIT: As a startup website its currently better that I save disk than saving processing time. I don’t have much money for large amount of space at this moment. Hopefully it will change when the site launches.

Any ideas? Thanks guys and girls.

Answer 1

I assume you can ‘control’ the urls to the resized images, so for example the full-sized image might be referenced as <img src='uploads/myphoto.jpg'/> the thumbnail could be to an ASPX or ASHX like <img src='uploads/myphoto.jpg.ashx'/>?

This article on CodeProject – Dynamic Image Resize seems to have exactly the source code you are looking for (and although it’s in VB, it shouldn’t be hard to port if you’re a C# person). Hope that helps.

Finally, I’d encourage you consider the various forms of caching (both using Http-Headers, to ensure the images are cached at the client or proxy whenever possible; and using built-in ASP.NET features to avoid unnecessary processing of the same images over-and-over).

Although you’ll be saving disk-quota, you’re effectively slowing down every other page/request… just a thought.