I found Rob's article in the Newsletter of BirdLife Southern Queensland Photography, Volume 2 Number 1 January 2013

Image Resizing article

If there's a more recent version, perhaps Rob will let us know.

Bye for now,
les

Hi Les and Simone

I'm not sure where that article is either but I have written basic image processing articles which deal with the issue of downsizing and loss of sharpness that results. This was written up in a two part series in the newsletter ( Dec 2015 and April 2016) - you will need to be logged in to the site to see these newsletters.

You can find my (somewhat old, but still applicable - although our website size limits have changed since it was written) article in our Resources - Libraries & Documents section. Open the Information folder, and the article is there; it's called "Cropping and resizing Images". Click here to open it directly.

Rob

Les,

Thanks heaps for the info. I've just downloaded GIMP and I'm keen to start uploading my images to Birdlife Photography.

Cheers,
Simone

Good luck!

Hi Simone

On your original question of loss of sharpness that results from downsizing images, I notice Rob's resizing article doesn't mention the need to sharpen an image after downsizing. GIMP has a sharpening tool but I think it's only the unsharp mask, which is quite powerful and effective but can be tricky to use well. Some sharpening after downsizing is important if you want to recover some of that sharpness. I personally don't use unsharp mask because it can create some strange visual effects, especially if applied to strongly. And over-doing it is a common mistake. As I'm not an unsharp mask user, I'm probably not best placed to advise on this tool but there's plenty on the web and even some articles in our older newsletters. Take a look at this one for example.

BLP sharpening article