Remember the days of sports entertainment before HDTV? Spotting a golf ball that landed in the rough was eye-squintingly difficult — and nearly impossible if it found the bunker. Both NFL and soccer fans missed a significant portion of the action because the 4:3 aspect ratio of old tube TVs focused around the ball while sacrificing the rest of the field. Hockey was so difficult to watch on TV that FOX tried a gimmick where they virtually highlighted the puck with a blue circle so viewers could better follow it around the rink.
Once fans experienced the in-your-face clarity and widescreen format of HDTV, there was just no going back. The same is true in the world of surveillance.
The HDTV journey began in 1998 with the first NFL game broadcast in high-definition. Within a decade, standard-definition NFL broadcasts were no more. In 2005, if you journeyed to Tokyo’s Akihabara district — known to some as the consumer electronics capital of the world — it was clear that analog was dead and 720p/1080p HDTV were the new preferred formats.
At the same time, the point-and-shoot digital camera market was saturated by relatively inexpensive megapixel models. From the early- to mid-2000s, the digital camera market saw rapid resolution development and the most popular camera sellers went from 1MP to 8MP and up to 12MP, where the lens became the limiting factor. But then something really interesting happened: the original iPhone launched in 2007 with a 2.0MP camera. From 2008 to 2010, the “more megapixels” trend in the digital point-and-shoot camera market took a step back, and sales were soon dominated by the 2.0 — 5.0MP camera phone. But even though the point-and-shoot megapixel race slowed down, camera phones literally put megapixel technology at the fingertips of millions.
Security personnel who had been enjoying HDTV in their homes and megapixel on their phones started clamoring for the same superior viewing experience and performance from their surveillance systems. Fortunately, surveillance manufacturers had already set the R&D wheels in motion.
Megapixel vs. HDTV: What’s the difference?
High-resolution in security did not begin with the first HDTV surveillance camera — high-resolution cameras have actually been on the market since around 2003. But those precursors to HDTV had all been megapixel, just like their digital still photography counterparts. Yes, there is a big difference between HDTV and megapixel.
Megapixel strictly applies to one part of the image: the number of pixels in the field of view. It has no meaning in terms of frame rate, aspect ratio or color fidelity performance of the video. So whether the camera is 3, 5 or even 10 megapixels, a higher megapixel resolution does not necessarily mean it will provide better overall usable video quality than a camera with a lower resolution running in HDTV.
True, the more pixels you have, the more details you capture. This is great for forensic searches — provided you have a comparable megapixel-rated lens to achieve the true megapixel rating of the camera; however, because of the amount of pixel detail being captured by a high megapixel camera, bandwidth consumption rises accordingly. If you are facing bandwidth or storage constraints, then the frame rate of the megapixel video must be dialed back to accommodate the limits of the pipeline.
Some people confuse the issue by referring to a megapixel camera as “HD” — but it is not HDTV. HDTV is a standards-based format governed by the Society of Motion Picture and Television Engineers (SMPTE) that not only guarantees resolution (720p, 1080i or 1080p) but also the 16:9 widescreen format, frame rate and color fidelity of the video. HDTV provides a much better overall video viewing experience. This is why your smartphone takes 8MP snapshots but records in 720p or 1080p HDTV when you switch to video recording.
In January 2009, the security market launched the first HDTV-compliant surveillance camera. That crossover of HDTV standards from the consumer world to the security realm forever changed the industry’s outlook on surveillance; thus, 2009 is where our real “story of HD” began.
Details of HDTV
The two most common HDTV standards in the television world are SMPTE 296M and SMPTE 274M.
SMPTE 296M or HDTV 720p uses 720 scan lines and a refresh rate of 30 progressive scans per second. The standard defines the resolution as 1280x720 pixels in a 16:9 format with high color fidelity.
SMPTE 274M or HDTV 1080 uses interlaced (1080i) or progressive (1080p) scan lines and a refresh rate of 30 Hertz or 60 Hertz, which corresponds to 30 or 60 frames per second, in North America. The standard defines the resolution as 1920x1080 pixels in a 16:9 format with high color fidelity.
The HDTV standard is based on square pixels — similar to those used on computer screens; therefore, HDTV video from network video cameras can be shown on either HDTV screens or standard computer monitors. With progressive scan HDTV video, conversion or de-interlacing techniques do not need to be applied for the video to be processed by a computer or displayed on a computer screen.
Today, the majority of HDTV-compliant IP surveillance cameras sold in North America are 720p. Despite the initial race to own the cameras with the most megapixels, savvy security practitioners have learned that more pixels does not always mean better when it comes to usable video.
Driving HDTV Adoption in Surveillance
While the consumer market shift to HDTV is close to 100 percent, the security industry still has a long way to go. Market research estimates that 35 percent of the surveillance cameras sold in 2012 were IP cameras, and of those IP cameras, about 50 percent were HDTV-compliant. If you do the math, you can see that only 15-20 percent of the surveillance cameras sold last year were HDTV cameras. Industry experts predict that shift is going to accelerate in the coming year due to a number of factors:
1. There are a lot more HDTV camera choices. While the first HDTV cameras were only fixed box cameras, now security practitioners can chose from fixed, fixed dome, pan/tilt/zoom and even miniature covert all-digital HDTV cameras.
2. There’s an HDTV price point for everyone. The first HDTV cameras listed for $1,499 MSRP. Today, they can be purchased for less than $250.
3. HDTV cameras come with more options. The first HDTV cameras were pretty bare bones. The ability to achieve compliance to the HDTV standard and deliver the same video quality as seen in the living room was in itself a big accomplishment. Today’s HDTV-compliant cameras come with a number of image-enhancing features, like wide dynamic range (WDR) and extreme light sensitivity with full color fidelity at night.
4. Turning HDTV on its head. The standard format of HDTV compliance is a widescreen 16:9 aspect ratio. This matches the dimensions of today’s HDTV flat screen monitors and is perfect for monitoring perimeters, open lobbies and typical outdoor surveillance applications; however, the horizontal format left much to be desired when monitoring retail aisles, long hallways, tunnels or alleys because pixels on the sides were wasted on walls and shelving. Today, there are HDTV cameras that can operate in a portrait 9:16 format, which gives security better vertical coverage of narrow, long and high-stacked locations.
From Better Resolution to Smarter Surveillance
While high megapixel cameras will certainly be viable for special niche applications, industry experts expect HDTV to be the dominant choice in surveillance applications in the coming years. Therefore, while manufacturers will continue to push the envelope in terms of better performance and image usability, a more concerted effort will be focused on increasing the video intelligence of the camera to support more proactive surveillance.
To achieve proactive video through analytics and data mining, surveillance technology has to deliver three things: high image quality, powerful local processing and customized intelligent algorithms. As of now, HDTV provides the exceptional image quality. Many HDTV cameras support local storage and high capacity in-camera processing; and, with open software platforms residing inside IP cameras — which have essentially morphed into computers that can see — more third-party developers will jump into the surveillance arena to custom design intelligent algorithms for specialized security needs and smarter surveillance for all.
Where Does HDTV Go from Here?
As HDTV cameras continue to gain a larger foothold in the security world, many have asked where the next big technology breakthrough will occur. There are some preliminary discussions underway in the consumer market about a higher 4K resolution — which is now designated by the Consumer Electronics Association as Ultra HD.
But even if Ultra HD reaches consumers in the next few years, any impact on the security industry is probably quite far down the road. The same could be said for 3D technology or any improvements in electronic color fidelity. First, we must find a relevant and practical surveillance use for a new technology, and then manufacturers must rigorously test it to ensure that it works for critical security needs. Remember, it took more than a decade for the first HDTV security cameras to cross over from the consumer world.
Next big thing ideas aside, the surveillance manufacturing industry’s continued focus will be on improving HDTV-quality surveillance in all lighting conditions. After all, television shows and movies are shot in absolutely ideal lighting conditions — real-world video surveillance is far from that. Processing power improvements inside IP cameras will become increasing important in deciphering details in low and varying lighting conditions. We saw dramatic improvements to WDR and low light video technology in 2012, and in 2013 we will see these features rolled out across different form factors (fixed box, fixed dome, PTZ) and price points.
Fredrik Nilsson is the general manager for Axis Communications in North America. He is the author of “Intelligent Network Video: Understanding Modern Video Surveillance Systems,” published by CRC Press. His popular “eye on Video” series can be found on www.SecurityInfoWatch.com. To request more information on Axis, visit www.securityinfowatch.com/10212966.