Can someone let me know if it's possible to edit images within joomla? I would like to be able to crop, annotate, etc an image within joomla. The only way I can see it's possible would to be to completely delete the image and upload the re-edited image - which would be painful, as I have so many.
You can use an extension like JCE Image Manager Extended.
Image Manager Extended adds to the power and ease of use of the Image Manager with options for resizing and thumbnailing images on upload, quick and easy image popup creation, a unique Thumbnail Editor and an Image Editor.
The image editor is fairly powerful, and includes functions like Resize, Crop and Rotate, plus a few image effects.
Note that this is a subscription based extension.
In cases where I have to edit many images in Joomla, I usually download the entire /images/ folder, edit the files locally using a real image editor, and then upload the files again, replacing the existing images.
If you have cPanel access, you can compress the entire folder, since it's a lot faster to download a single (large) file than hundreds or thousands of small image files. Then compress the images again when you're ready to upload the, and unpack everything on your server.
Disclaimer: I am not in any way affiliated with JCE or joomlacontenteditor.net.