LED walls are gaining ground as the primary large-format video displays in large church auditoriums and sanctuaries. Performance and price are driving this trend: LED walls can deliver much more brightness than projection screens, which really matters in high ambient light situations. At the same time, LED walls typically consume less power than video projectors and throw off less heat (reducing air conditioning requirements), while the absence of lamps that burn out lowers maintenance costs. (While LED walls are expensive to buy, the price has been dropping substantially in recent years.)
With the trend towards LED walls in churches comes a need to incorporate image processing into these displays systems—and yes, there is a need. “The ultimate purpose of image processing is to deliver the production’s vision as the designers, video producers, directors, and, of course, their clients intended it to be,” explains Sean Sheridan, Brompton Technology’s regional technical manager, Americas. “This applies to church and worship as much is it does to any other market.”
“If the screens don’t look right, if the image doesn’t ring true, then the display can become a distraction rather than the enhancement it’s intended to be. The message becomes harder to deliver.”
- Sean Sheridan, Regional Technical Manager, Americas, Brompton Technology
Sheridan continues, “If the screens don’t look right, if the image doesn’t ring true, then the display can become a distraction rather than the enhancement it’s intended to be. The message becomes harder to deliver. And we know nothing is more important to a church service than the message.”
What Image Processing is
According to the online Lexico dictionary, image processing is the “analysis and manipulation of a digitized image, especially in order to improve its quality.”
When it comes to church AV, “the term ‘image processing’ encompasses a lot of different aspects of video production,” says Andrzej Lubaszka, Analog Way’s chief technologist. “In the case of a church video wall, a lot of those aspects can become important all at once, as you typically need some kind of video production for camera switching; presentation video switching aspects to deal with slide decks, hymn numbers, and lyrics; scaling/window compositing onto a large canvas to feed a multi-output video wall; edge-blending downstage monitors; plus signal conversion for feeds to the nursery, remote viewers, and more.”In the past, these image processing systems required dozens of boxes, complicated cabling, and entire rack rooms to house them. Today, manufacturers sell image processing solutions that “include all of those features in just one or two devices,” Lubaszka notes.
Calvary Church in Grand Rapids, Mich., installed a large Vanguard P4 Rhodium LED wall, but the third-party video processor introduced glitching, jumping and ghosting effects to the images. Analog Way arranged an on-site demo of the Ascender 16 processor to demonstrate a solution, which the church promptly purchased.
Why Image Processing Matters for Video Walls
Since it is possible to tune digital cameras to capture colors accurately during a live church shoot—helped by professional-quality lighting—some might argue that image processing for LED walls isn’t really necessary. But they’d be wrong.“The importance of image processing when it comes to LED video walls is that image processing can improve the accuracy of your grey and black levels,” says Max Perry, president of Vanguard LED Displays. “When you’re showing low-brightness images, you want to be able to see all of the different gradients being shown, rather than having your blacks ‘crushed.’”He continues, “Without image processing, you can lose a lot of your fine detail and fidelity in your LED walls. You can end up feeling that ‘this is okay, but I’m not seeing the full potential of what my display system has to offer.’”Sheridan echoes this point. “Without image processing, the likelihood that your LED wall displays your content as you imagined would not be very likely,” he says. “‘Good enough’ would be your best hope in this situation. And with increasingly discerning audiences with multiple HD TVs at home, and further adopting 4K displays with technologies like High Dynamic Range (HDR), hoping to just get by in this way becomes more and more difficult.”
Churches that add image processing equipment to the video playout chain avoid these problems, and keep their viewing attendees happy. “With processing, you significantly improve the quality of your image,” says Sheridan. Add in new enhancements like HDR into the image processing mix, and churches can deliver “better image quality, but without requiring finer and finer pixel pitches to achieve it.”
The Tessera S8 from Brompton Technology is a cost-effective processor for LED walls that offers high-quality image correction and color adjustment tools, like OSCA and Chromatune. These tools allow the content creators’ vision to be accurately conveyed on-screen.
Image Processing Options
Image processing for LED walls is not a one-size-fits-all solution. There are various levels of quality available depending on if a church buys a commercial-off-the-shelf (COTS) solution or turns to a manufacturer for something customized to their needs.“For LED walls, options range from the most simple ‘sending cards’ which have little in the way of adjustments available to ensure that the display looks the best that it can, to more full-featured processors, with numerous handles for color adjustments, image scaling, input and output mapping,” states Sheridan.
“This high-end of the quality range is where Brompton’s Tessera line of products firmly sit. Our features—such as OSCA (On-Screen Color Adjustment), Chromatune (color correction), PureTone (which ensures neutral color balance across the entire greyscale) and Thermacal (real-time compensation for thermal artifacts)—enables the user to create a custom image without the high cost that hardware/software R&D and production for a bespoke system would require.”“In terms of the image processor market, there tends to be a big divide between hardware based solutions and PC/software based solutions,” agreed Lubaszka.
“When you’re showing low-brightness images, you want to be able to see all of the different gradients being shown, rather than having your blacks ‘crushed.’”
- Max Perry, President, Vanguard LED Displays
“While software-based solutions that run on a user-supplied PC might seem like a good idea in the short run, we have found that the frustrations of dealing with the latest operating system updates, finding the right drivers, bogging down the system with other software, upgrade fees for the next software version, high frame delay, and other related problems often steer customers toward a more dedicated hardware based solution.”
Analog Way has been providing churches and other video customers with hardware-based image processing solutions for the past 30 years, he added. “Analog Way’s Aquilon (part of the LivePremier family) is a 4K/8K seamless presentation switcher and video wall processor, designed to deliver mission critical industrial grade performance for live events,” Lubaszka says. “Our Ascender and Nextage units (part of the Livecore Family) are our 2K/4K seamless presentation switcher and video wall processors, which offer a great solution at an affordable price point for projects that are based on 2K and 3G-SDI signals.”To ensure that churches get the right image processing solutions for their specific LED walls, Perry suggests calling in an expert. “I would recommend getting a technician who is familiar with the church’s video system and LED wall to select the right product for your needs,” he says. “If you buy the right top-of-the-line equipment and install it correctly, there’s no reason why you shouldn’t see immediate improvements in the quality of your video wall content, especially in those darker scenes.”
A Worthwhile Investment
Image processing is a worthwhile investment in any church video chain, including those whose outputs end up on LED video walls. In fact, it could be argued that image processing is particularly vital here, because the flaws found in unprocessed video will definitely stand out on these big, bright displays.This is why churches need to investigate image processing for their LED walls without delay. Otherwise, they’ll be limiting the video quality that their attendees are seeing and paying for, which is like feeding their high-end audio into entry-level loudspeakers.
