A picture library is more than just a "holding cell" for your graphics. It is possible to edit graphics within the library itself and to control versioning of the picture library contents.
Figure 13-7. Editing an uploaded picture
The benefit of requiring that an image be checked out in order to be edited is that only one person can edit an image at a time. If the image is checked out and then another user attempts to check it out, the second user will receive a message indicating the image is unavailable. Once the first user has checked the image back into the library, any other user can access it and edit the graphic further. This procedure is more important for pictures than for documents, since it is almost impossible to "merge changes" on a picture:
Open the picture library, either by clicking its name in Quick Launch or by clicking View All Site Content and then clicking the library's name.
Click Settings and select Picture Library Settings from the menu.
Under General, click "Versioning settings," as seen in Figure 13-8.
Under Require Check Out, click the Yes radio button next to "Require documents to be checked out before they can be edited," as shown in Figure 13-9, and then click OK.
Figure 13-8. Modifying ...