Options for storing images in viewports. 
Use Cache Image: The viewport image will be stored as a picture, so that the image does not have to be regenerated. This is handy for large, rendered images that can take time to generate. Update: If Manual is selected, the generated picture will be updated after you select Update Viewport Cache.The remaining options on this page control the quality and size of the generated picture.
Manage space
Manage content
Integrations