This probably has nothing to do with zenphoto specifically, but I thought I'd ask anyway. What would cause jaggy images during resizing?

Take a look at the horizontal power lines in this image, resized by zenphoto: http://img708.imageshack.us/img708/994/imagezp.jpg

Now, the same image resized by Photoshop: http://img186.imageshack.us/img186/7671/imageps.jpg

Changing JPG quality in zenphoto's settings doesn't make any difference.

Any thoughts?

Generated images are cached so unless you clear the cache Zenphoto will always server the same image regardless if you change settings. I guess the image is a little too much sharpened.

Thanks for responding.

After changing the JPEG settings, I did indeed regenerate the cache.

Also, I have sharpening turned off. I suspect the issue is simply that GD does a poor job of resizing the image compared to more advanced image editing programs. Not really a zenphoto issue, but I thought I'd mention it all the same.