Link to download image instead of view image

I need to provide website visitors a link to download an original high resolution image. If I simply link to the image with a href="image.jpg", the browser displays the image. How do I make the browser download it?

I'm using amazon S3 to server these images... If this requires having a special header set on the image, I'm sure it's possible.. but I also want to display these images sometimes. Any tips on making this work with S3 would be great.

You are right. There are some headers needed to do this. These would be:

Content-type: image/png
Content-Disposition: attachment; filename="some_image.png"

I am not sure how S3 handles this but if you want do display these images, the Content-Disposition header should be left out.

EDIT: Displaying the image via <img src="some_image.png" alt="" /> continues to work even with both headers being sent. The image displays nicely in my tests.

You can use the content-disposition header to let the client download the image:

Content-Disposition: attachment; filename=<file name.ext>