Configuring cobby to prevent image duplicates
The default behavior in Magento when updating images without changing the image name is to rename the new image to ImageName_1. However, if you just wanted to update the image (e.g. better resolution, additional text in the image) you will fill your server with 'orphaned' images over time.
cobby fortunately offers the possibility to overwrite images with identical names when saving. The feature can be enabled in the Magento backend in the cobby settings under System -> Configuration -> Services -> cobby -> Advanced.
If you set Overwrite images to Yes, newly uploaded images, if the same image name already exists, will not be renamed to image_name_1.jpg. The existing image on the server will be overwritten with imagename.jpg.
Setting Overwrite Images to No will apply the old behavior and Magento will rename new images by appending an underscore followed by a number to the image name.
Don't forget to save changes on the configuration page with Save Config.