The objective of this research is to integrate multiple quality-constrained cell-phone-based pico-projectors as to create quality output and improve the viewing experience of users 'on the go' during a multimedia session, i.e., watching a video, or sharing a multimedia presentation. The proposed approach is to develop coding and decoding schemes to allow flexible split stream media delivery that takes into account the number of displays for image partitioning and accommodates a range of resolutions, frame rates, and device power resources. Additionally, novel synchronization schemes that integrate display synchronization and video/audio stream synchronization across multiple devices will be investigated. Current multi-projector registration techniques need to be modified for resource and quality sensitivity for use in low-quality pico-projectors.
The project proposes a new paradigm of resource management, device synchronization and video coding/decoding for portable multimedia devices to collaboratively deliver an enhanced viewing experience for users, where 'enhanced' refers to frame rate, image resolution, brightness, audio quality, and power savings for longer viewing. This paradigm parallels the MIMO concept in wireless communications by introducing spatial diversity in video display. MIMO enhances the data rate and/or the signal quality, the results of this project is expected to enhance the image resolution and/or brightness.
The proposed paradigm will allow multiple users to pool the resources of mobile portable devices to produce a higher quality, energy/resource efficient output, anywhere, anytime. This will impact users 'on the go' in ad hoc settings, ranging from media sharing in social milieus to first responders and emergency workers requiring higher quality image output in the field.
The first wave of ultra-portable projectors, called pico projectors often less than an inch thick, is now beginning to appear in the market in response to the emergence of advanced portable devices such as smart phones, portable media players, and high-end digital cameras, which have sufficient processing power and storage capacity to handle large presentation materials but little real estate to accommodate larger display screens. Such portable systems are projected to be one of the primary devices to be used by younger people for ubiquitous sharing of all possible media initiating novel social interaction paradigms. In fact, iSuppli predicts that shipments of embedded pico projectors will grow sixtyfold from 50,000 units in 2009 to more than 3 million in 2013. Pico-projectors consume 1.5 Watts, or about 200 times less power than a standard 2500 lumens projector consuming 300 Watts, and are about 25-35 times lighter than a standard projector and weigh about 4-5oz when a standard projector weighs about 7-11lbs. This allows extreme miniaturization and reduction in weight so that they can be embedded within small devices like cell phones or media players. Indeed, several available cell phone models from such manufacturers as Samsung are already equipped with integrated projectors. Nikon COOLPIX S1000pj series of digital cameras is another example of devices with embedded projectors that are already in the market. Furthermore following recent patents of Apple on pico-projectors there are high anticipations that near future generations of iPhones, iPods and iPads would have integrated projectors. Pico projectors also have limitations. Compared to 2600 lumens for a common commodity projector, the pico projector emits around 10 lumens of light, providing about 300 times lower brightness for similar size image. Compared to a commodity projector at HDTV resolution, an embedded pico projector offers a small resolution of 480 x 320, or about 15 times lower. Due to those limitations, the image quality of embedded pico-projectors will take a while to become comparable to common commodity projectors, and a bright HDTV pico-projector will be next to impossible, for the next decade or two. Thus, the current generation of users is accustomed to a much higher quality media content than what the pico projectors are offering today or will be able to offer in the foreseeable future. However, unlike any other alternate mobile display technology, pico projectors have a distinctive advantage – the image displayed from multiple pico projectors can be overlaid on top of each other or tiled to create a dramatically improved display in both brightness and resolution. Imagine when pico projectors are commonly integrated in mobile devices. Due to the power dissipation constrains, the cost and the technology limitations, a single mobile projector can only offer limited resolution and brightness resulting in low quality viewing for the users. However if they use multiple projectors already available in their mobile devices, using a tiled setup, a much larger higher resolution image can be constructed, replacing a high resolution mobile projector while also benefiting from aggregating individual device resources such as processing power, battery capacity and network bandwidth to deliver a higher quality video. The resulting large size image can also provide the possibility of trading off the image size with brightness by adjusting the projectors’ throw distance which can help to increase the brightness of the projected image further improving the viewing experience for the users. The goal of this research is to provide proof of concept research in collaborative media delivery, complex synchronization schemes for display, video and audio integration and new coding/decoding schemes that enable flexible media delivery to accommodate a range of resolutions, frame rates, and image partitioning. A collaborative video playback on mobile projectors has been designed, built, set out and managed only through visual feedback. More specifically we introduce a camera-based video synchronization algorithm that allows a federation of projection-enabled mobile devices to collaboratively present a full video stream that consists of multiple sub streams, each streamed to a different mobile device constituting the ensemble. Since the synchronization does not use any wireless network infrastructure, it is independent of network congestion and connectivity. We combined our synchronization method with existing distributed registration techniques to demonstrate a synchronized video stream for a collaborative federation of four projectors arranged in a 2 × 2 array. To the best of our knowledge, this is the first time that camera-based techniques have been used to mitigate network uncertainties to achieve accurate video synchronization across multiple devices. By pooling the resources of mobile portable devices to produce a higher quality, energy/resource efficient output, anywhere, anytime, users 'on the go' in ad hoc settings will be enabled with far-reaching capabilities, ranging from media sharing in social milieus to first responders and emergency workers requiring higher quality image output in the field.
