Tchaikovsky Symphony number four opens with the full force of the combined brass section at fortissimo introducing the main theme. One minute thirty seconds later, we are left with nothing but bassoon – barely audible above the noise floor of most home audio systems. If you try to take that CD into your car, you’re facing a serious problem. Turn the volume on the intro down to the point where it doesn’t distort your automotive sound system and a minute and a half later you’ll be listening to nothing but road and wind noise and the drone of your engine. Turn it back up at that point to hear the bassoon, and you’re just minutes from blowing the ears off your rear-seat passengers with a wall of clipped and distorted chaos reminiscent of the Chicago Symphony brass section in an airport restroom. When we take our entertainment on the road, the dynamic range we savor at home becomes a liability.
The same thing applies when you try to take that movie that looks so awesome on your plasma TV with 10,000:1 contrast ratio onto a mobile device with… 400:1? Ouch! It gets worse – that 400:1 is only in a dark room with the backlight turned up. Turn down the backlight and the highlights drop away. Move into brighter ambient light and the shadow details get absorbed into a grey reflective blob. Combine those effects and the actual contrast ratio can dip near 100:1. The result of that contrasty video playing back on your low-contrast mobile display is that most of the highlights blast away to pure white, and most of the shadow detail drops off to pure black. The quality of the video-viewing experience is drastically diminished. Turn up the backlight in an attempt to compensate, and your batteries burn off faster than you can believe. (Do you know that about 50% of many mobile devices’ power is burned in the backlight?).
Wouldn’t it be wonderful if we had an LCD driver device that knew the ambient light and backlight settings and could use those to calculate the available contrast range of the display, then could analyze the video stream and do pixel-by-pixel dynamic range and color correction? It would improve our “effective” contrast ratio considerably and would keep us from having to constantly crank around on the backlight settings as we move into different environments. Of course, running with less backlight means we’d be saving battery life too, allowing us to get all the way to the end of the video instead of chopping off the last ten percent just when the bad guy is about to…
You’ve probably guessed that we wouldn’t be writing about this if somebody hadn’t already done it. And, if you’re one of those super-clever types who read the title, you may even know who it is. QuickLogic has just announced a collaboration with Apical Limited to produce programmable display driver chips that take advantage of Apical’s Visual Enhancement Engine (VEE) algorithm. The new devices are aimed at high-volume, low-power applications like smart phones and portable media players where cost, power, display performance, and time-to-market are all at a premium.
QuickLogic will be licensing a version of Apical’s patented iridix core to deploy on their PolarPro and ArcitcLink super-low-power programmable solution platforms. Version 1.0 of VEE is available today on the PolarPro platform, and version 2.0 will be incorporated into the next-generation ArcticLink solution platform. Apical has already penetrated the highly-competitive digital camera market with this technology – you’ll find it in offerings from companies such as Sony, Olympus, and Nikon with trade names like “D-Range Optimizer”, “Shadow Adjustment Technology (SAT)”, and “D-Lighting” respectively.
The technology considers ambient light level, battery level, and backlight level and works to optimize viewing quality and battery life. QuickLogic claims that VEE can take that 110:1 contrast ratio available with a mobile device in high ambient light with the backlight at 30% and return an “effective contrast ratio” back up in the 600:1 range. QuickLogic’s implementation includes the license for VEE in the cost of the device, so you need to deal with only a single supplier. At the system level, you get all of the advantages we’ve discussed in the past of QuickLogic’s CSSP (Customer-Specific Standard Part) offering – high performance, low cost, very-low power consumption, fast customization and turnaround time, and small form-factor (the VEE-enabled devices are available in WL-CSP at 0.4mm pitch and 6x6mm BGA at 0.5mm pitch.)
Fig. 1 Original (above). Fig. 2 with VEE (below)
While you may have done a manipulation similar to this on your vacation photos using Photoshop, doing it on a video stream in real time and compensating for environmental changes in the process requires the kind of performance you get by accelerating the algorithm in hardware. Doing VEE-like operations in software would require some serious MIPS, and packing those MIPS into a mobile device would burn batteries faster than even a backlight! According to QuickLogic, the algorithm translates very nicely into parallelized hardware, however, giving plenty of throughput with a minimal amount of power consumption.
The upcoming ArcticLink II version of VEE includes a D-PHY for up to WVGA resolution support. In the PolarPro implementations available now, the hardware portion of the VEE algorithm is implemented in the ViaLink fabric. In the newer version, VEE will be included as a dedicated, optimized hardware block. This will give higher performance and lower power consumption and will consume less chip area – leaving more programmable fabric space for you to pull additional functionality into the device.
You may design-in one of these devices for the VEE capability, but you’ll probably end up pulling some additional capabilities in as well. QuickLogic has a large library of functional blocks that you can mix-and-match in your customized device, and the natural tendency seems to be to incrementally pull chunks of your design into the CSSP for lower cost, lower power, and smaller footprint.
For QuickLogic, this represents a potentially enormous market as VEE offers a substantial upgrade to the user experience in mobile devices. With mobile multimedia experience rapidly becoming a decision criterion for customers, we expect to see a big interest in mobile designers integrating this technology. Unlike so many features being designed into smartphones, this one doesn’t take server or network support and doesn’t require the approval and blessing of the carrier to make it to market. For many mobile device design teams straining to find ways to differentiate their offerings in such a constrained market, this one seems like a gift.