CropTool is a tool for cropping images (currently only jpegs) at Wikimedia Commons. It's inspired by User:Cropbot, but adds some new features, such as OAuth for authorization and automatic border detection. CropTool runs at Tool Labs, and the source code is available at GitHub. Recent usage of the tool is available from recent changes.
If you'd like to try the tool, many of the images in Category:Images with watermarks need to be cropped.
You can try the tool by going to //tools.wmflabs.org/croptool/, but it's more convenient to have a link in your "Tools" menu at Wikimedia Commons. To set that up, you need to go to your gadget settings and enable the CropTool gadget.
|1. Here is an image that should have it's border removed. Start by clicking "CropTool in the "Tools" menu.|
|2. To use CropTool, you need to authorize it to use your Wikimedia Commons account using OAuth.|
|3. This will take you to a secure MediaWiki OAuth server. Note that your password is never transmitted to CropTool.|
|4. Make a selection with the cursor and press "Preview". In this case, we need to make an exact (precise) crop, since we want to keep as much of the image as possible, while removing the border.|
|5. Looks good, so we can go ahead and "Upload to Commons".|