Apple banners, flags, posters go up at Bill Graham Civic Auditorium ahead of Sept. 7 event

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Like the media gathering that introduced the world to iPhone 6s last September, Apple is expected to introduce new iPhones, Apple Watch and Beats headphone hardware in a keynote presentation tomorrow.

Apple has a habit of teasing major announcements in its promotional materials. For example, posters adorning Bill Graham Auditorium last year featured an Apple logo design that turned out to be a take on Siri's colorful wave form animation. At the event, Apple debuted a host of Siri improvements for iOS and integration with Apple TV via tvOS.

This year, Apple's invitation recreates the company's iconic logo with a series of out-of-focus points of light. The clever use of "good" bokeh, a term describing the quality of blur produced in a photographic image, suggests big improvements are in store for iPhone's cameras. Posters bearing the same image were installed at the auditorium over the weekend.

Apple is indeed anticipated to announce significant upgrades to iPhone's photo-taking capabilities, with a 12-megapixel sensor rumored for inclusion on the 4.7-inch model and advanced dual-lens technology for the larger 5.5-inch version.

Rumors also indicate an Apple Watch refresh with GPS capabilities, a higher capacity battery and better waterproofing is primed to debut tomorrow. Apple's Beats brand is also expected to get some stage time.

Not much else can be gleaned from the auditorium's decorations, which includes a marquee out front that reads "Special Event." As for functional building preparations, Apple has completed running cable from inside the auditorium to trucks outside labeled "TV Control Room," presumably for its scheduled live stream.

AppleInsider will be covering Apple's announcement live from Bill Graham Auditorium tomorrow from 10 a.m. Pacific, 1 p.m. Eastern.