Image DimensionsImage Format Selection: Accept, WebP, JPEG 2000, and JPEG XRImage QualityQuality and Image Byte SizeQuality Index and SSIMSelecting SSIM and Quality Use CasesCreating Consensus on Quality IndexQuality Index ConclusionAchieving Cache Offload: Vary and Cache-ControlInforming the Client with VaryMiddle Boxes, Proxies with Cache-Control (and TLS)CDNs and Vary and Cache-ControlNear Future: KeySingle URL Versus Multiple URLsFile Storage, Backup, and Disaster RecoverySize on DiskCost of MetadataDomain Sharding and HTTP2How Do I Avoid Cache Busting and Redownloading?How Many Shards Should I Use?What Should I Do for HTTP/2?Best PracticesSecure Image DeliverySecure Transport of ImagesSecure Transformation of ImagesSecure Transformation: ArchitectureSummary