High-dynamic-range (HDR) is a process used to reproduce a more vast spectrum of luminosity. The technology to produce HDR imagery is relatively new and is most commonly used in photography. HDR equipped cameras take multiple exposures to highlight the dark and light information in a scene. The exposures are then combined into a single image that more accurately recreates how the human eye perceives light and color. While the process is quite popular among photographers and filmmakers, it has also been a favorite for computer artists.
Digital artists employ the use of HDR to achieve a more realistic look to computer generated elements. The process, called high-dynamic-range rendering or HDRR, is slightly different for creating digital imagery. Rather than using image processing to combine exposures, HDRR renders images based on calculations done in HDR. Compatible TV’s and monitors can then display the digital imagery by using panels which offer a wider gamut of colors compared to standard RGB hardware. According to Nvidia, the color gamut can be expanded by a factor of two, which accounts for close to three quarters of the visible color spectrum.
This means that the image quality is significantly higher. HDR boosts the contrast between white and black, making dark areas richer and light areas brighter. It also increases saturation so colors appear more lush. All of the elements combine for a much more vibrant and realistic image. It’s a method for rendering CG elements that has been widely used in everything from architectural visualization to special effects in films. The only digital realm that hasn’t been able to utilize the technology until now, is the video game industry.
As opposed to CG films that render scenes into individual frames which are then compiled, video games are displayed in “engines” that run in real-time. This real-time display has prevented developers from integrating HDR technology into games due to the intense hardware requirements. While “modifications” have allowed some PC titles to incorporate HDR, it has been largely absent from consoles and the mainstream market until recently. In September Sony revealed that the PlayStation 4 was capable of utilizing such technology. After a firmware update, released only a weeks after the announcement, all PS4 consoles are now able to display games in HDR. Alongside the PS4, Microsoft’s newly released Xbox One S also posses the ability to take advantage of the dynamic rendering technique.
However, in order to utilize the new functionality, players will need to have access to Ultra HD Premium Certification (UHD) televisions. Although UHD is a characteristic native only to 4K TV’s, not every 4K set is capable of HDR standards. It’s important to pay close attention and research what options are available when looking to purchase an HDR capable TV.
To supplement the new advancements in hardware, most engines available to developers now support HDR as well. Although the technology is still in its infancy and can only be seen in a handful of current titles, it’s still a huge step for the industry. Access to this technology allows developers to create a more immersive experience for players. Dynamic lighting and effects is a major leap for the graphical fidelity of games. Games can now be visualized with more realism than ever before. It’s an exciting time for both players and developers alike as the industry can finally harness the powerful capabilities of HDR.
Side by side comparison of standard rendering (left) and HDR rendering (right) taken from Half-Life 2: Lost Coast. (image courtesy of Wikipedia and © Valve Corporation).