
Anyone who's taken a photo with a digital camera is likely familiar with a noisy image: discolored spots that make the photo lose clarity and sharpness.
Many photographers have tips and tricks to reduce noise in images, including fixing the settings on the camera lens or taking photos in different lighting. But it isn't just photographs that can look discolored - noise is common in computer graphics, too.
Noise refers to the random variations of brightness and color that aren't part of the original image. Removing noise from imagery - which is becoming more common in the field of image processing and computer vision - is known as denoising.
Image denoising uses advanced algorithms to remove noise from graphics and renders, making a huge difference to the quality of images. Photorealistic visuals and immersive renders could not be possible without denoising technology.
What Is Denoising? In computer graphics, images can be made up of both useful information and noise. The latter reduces clarity. The ideal end product of denoising would be a crisp image that only preserves the useful information. When denoising an image, it's also important to keep visual details and components such as edges, corners, textures and other sharp structures.
To reduce noise without affecting the visual details, three types of signals in an image must be targeted by denoising:
Diffuse - scattered lighting reflected in all directions;
Specular or reflections - lighting reflected in a particular direction; and
Infinite light-source shadows - sunlight, shadows and any other visible light source.
To create the clearest image, a user must cast thousands of rays in directions following the diffuse and specular signals. Often in real-time ray tracing, however, only one ray per pixel or even less is used.
Denoising is necessary in real-time ray tracing because of the relatively low ray counts to maintain interactive performance.
Noisy image with one ray per pixel. How Does Denoising Work? Image denoising is commonly based on three techniques: spatial filtering, temporal accumulation, and machine learning and deep learning reconstruction.
Example of a spatially and temporally denoised final image. Spatial filtering selectively alters parts of an image by reusing similar neighboring pixels. The advantage of spatial filtering is that it doesn't produce temporal lag, which is the inability to immediately respond to changing flow conditions. However, spatial filtering introduces blurriness and muddiness, as well as temporal instability, which refers to flickering and visual imperfections in the image.
Temporal accumulation reuses data from the previous frame to determine if there are any artifacts - or visual anomalies - in the current frame that can be corrected. Although temporal accumulation introduces temporal lag, it doesn't produce blurriness. Instead, it adds temporal stability to reduce flickering and artifacts over multiple frames.
Example of temporal accumulation at 20 frames. Machine learning and deep learning reconstruction uses a neural network to reconstruct the signal. The neural network is trained using various noisy and reference signals. Though the reconstructed signal for a single frame can look complete, it can become temporally unstable over time, so a form of temporal stabilization is needed.
Denoising in Images Denoising provides users with immediate visual feedback, so they can see and interact with graphics and designs. This allows them to experiment with variables like light, materials, viewing angle and shadows.
Solutions like NVIDIA Real-Time Denoisers (NRD) make denoising techniques more accessible for developers to integrate into pipelines. NRD is a spatio-temporal denoising library that's agnostic to application programming interfaces and designed to work with low rays per pixel.
NRD uses input signals and environmental conditions to deliver results comparable to ground-truth images. See NRD in action below:
With NRD, developers can achieve real-time results using a limited budget of rays per pixel. In the video above, viewers can see the heavy lifting that NRD does in real time to resolve image noise.
Popular games such as Dying Light 2 and Hitman III use NRD for denoising.
NRD highlighted in Techland's Dying Light 2 Stay Human. NRD supports the denoising of diffuse, specular or reflections, and shadow signals. The denoisers included in NRD are:
ReBLUR - based on the idea of self-stabilizing, recurrent blurring. It's designed to work with diffuse and specular signals generated with low ray budgets.
SIGMA - a fast shadow denoiser. It supports shadows from any type of light source, like the sun and local lights.
ReLAX - preserves lighting details produced by NVIDIA RTX Direct Illumination, a framework that enables developers to render scenes with millions of dynamic area lights in real time. ReLAX also yields better temporal stability and remains responsive to changing lighting conditions.
See how NRD helps create rich, detailed graphics in Hitman 3:
Learn about more technologies in game development.
Most recent headlines
11/12/2025
Dalet, a leading provider of cloud-native, end-to-end media workflow solutions, ...
01/12/2025
L3Harris and PentenAmio formalise their teaming agreement at MilCIS 2025, streng...
01/12/2025
Artemis II is NASA's first crewed flight test of the Space Launch System rocket and Orion spacecraft. The crew, from left: Commander Reid Wiseman, Pilot Vic...
01/12/2025
IRVINE, Calif. Wooden Camera has introduced its new Accessory Collection for the Canon EOS C50. The new lineup includes a low-profile, gimbal-ready cage, expand...
01/12/2025
WASHINGTON The Federal Communications Commission has released a tentative agenda for its Dec. 18 Open Commission Meeting that will include a vote on a report an...
01/12/2025
In most years, a graph of annual local TV ad spending is about as predictable as an electrocardiogram of a reasonably healthy patient in a doctor's office. ...
01/12/2025
Many industries have seen big-ticket hardware turn into software. Switchers, though, demand a combination of real-time performance and sheer bandwidth that has ...
01/12/2025
GENEVA Shanghai will host the next quadrennial Radiocommunication Assembly (RA-27) and World Radiocommunication Conference (WRC-27), Oct. 11-Nov. 12, 2027. This...
01/12/2025
NEW YORK Just in time for Giving Tuesday tomorrow (Dec. 2), the Broadcasters Foundation of America is seeking out donations to help television and radio industr...
01/12/2025
STOCKHOLM, Sweden Net Insight CEO Crister Fritzson has informed the company's board that he will retire from the video transport and media cloud technology ...
01/12/2025
01 Dec 2025
Kyivstar and Ukrainian Ministry of Digital Transformation Select Go...
01/12/2025
The prequel to the global hit Sky Original mob crime saga, Gomorrah' is a s...
01/12/2025
Featuring Florence Welch, Red Hot Chilli Peppers' Flea, designer Bella Freud...
01/12/2025
Back to All News
A Down to Earth, All Too Relatable Hero: Cashero' Teaser ...
01/12/2025
In the rush to deliver content to every screen, many broadcasters overlook one of the most crucial steps in the workflow: format and frame rate conversion. Get ...
01/12/2025
Fox Corporation Chief Financial Officer Steve Tomsic to Participate in Upcoming ...
01/12/2025
Arvato Systems' Virtual Private Cloud (VPC) Receives BSI C5 Certification (T...
01/12/2025
Summary This short video gives you an summary of the changes in under two minutes.
--...
01/12/2025
As the festive season approaches, RT Supporting the Arts is proud to showcase a...
01/12/2025
Researchers worldwide rely on open-source technologies as the foundation of their work. To equip the community with the latest advancements in digital and physi...
01/12/2025
Festive specials of Christmas in Kilmainham presented by Marty Whelan, High Road Low Road, Callan Kicks the Year and Keys to My Life
Ring in the New Year with ...
01/12/2025
Architect and television presenter Hugh Wallace, best known to RT audiences as a long-serving judge on Home of the Year, has died at the age of 68.
In a state...
28/11/2025
Nadia Fall attends the 2025 Sundance Film Festival premiere of Brides at the Egyptian Theatre on January 24, 2025, in Park City, Utah. (Photo by Donyale West/...
28/11/2025
It's easy to ignore those little red update available badges. But when it ...
28/11/2025
WASHINGTON Federal Communications Commission has released a tentative agenda for the December Open Commission Meeting scheduled for Thursday, December 18, 2025 ...
28/11/2025
The Professional Fighters League is looking to super-serve fans of mixed martial...
28/11/2025
Fubo has released in beta on select Roku devices a new feature that lets users display up to four simultaneous streams at once....
28/11/2025
The WNBA playoffs and Week 4 of the NFL regular season highlight the list of live sports events airing on television this weekend....
28/11/2025
The 32nd class of honorees to the B+C Hall of Fame took to the stage at New York's Ziegfeld Ballroom on September 26 for a gala induction event. Click below...
28/11/2025
We hold in our hands the very last Next Text for Next TV, the weekly back-and-fo...
28/11/2025
DirecTV said it made a deal with EchoStar to buy EchoStar's video businesses, including satellite-TV provider Dish TV and virtual MVPD Sling TV, for $1 plus...
28/11/2025
The Broadcasting+Cable Hall of Fame, the premier industry event paying tribute to the influencers, innovators and shining lights of broadcast, cable and streami...
28/11/2025
Friday 28 November 2025
Sky Sports x Slawn drop limited-edition football jersey...
28/11/2025
Rohde & Schwarz shows resilience in a challenging environment, revenue exceeds t...
28/11/2025
Unwrapped: The Toy Show Appeal - airing this Sunday on RT One and RT Player- s...
27/11/2025
LONDON Vizrt has added several AI-driven advanced features offering improved speed, intelligence and accuracy in the newest version of its media asset managemen...
27/11/2025
Prime Video has launched AI-powered video season recaps in a beta version for select English-language Prime Original series in the U.S., a move Amazon is callin...
27/11/2025
Back to All News
Netflix's Raat Akeli Hai: The Bansal Murders Marks a Grand...
27/11/2025
27 Nov 2025
GSMA brings M360 Eurasia 2026 to Samarkand in partnership with VEON...
27/11/2025
Tahar Rahim and Izuka Hoyle star in the gripping six-part Sky Original from Acad...
27/11/2025
Thursday 27 November 2025
Sky Arts Reveals the Nation's Greatest Basslines - and Queen Reign Supreme
The UK's most iconic basslines have been revealed...
27/11/2025
Back to All News
Stranger Things 5': Prepare for One Last Adventure With O...
27/11/2025
The media industry has a paradox at its core. It's an industry built on light, color and imagination, yet behind the scenes, it's powered by one of the ...
27/11/2025
Rating reflects rating progress across areas including policies, diversity & inclusion, health & safety and Net Zero leadership
Winchester, UK, 27 November 202...
27/11/2025
What are the industry standards for Retail Media? Kathryn explains that certification is based on the IAB Europe Retail Media Measurement Standards and the IAB ...
27/11/2025
World champion boxer and Irish sporting icon Katie Taylor will be in studio this...
27/11/2025
Roblox, one of the world's most popular online gaming platforms for primary ...
27/11/2025
Black Friday is leveling up. Get ready to score one of the biggest deals of the season - 50% off the first three months of a new GeForce NOW Ultimate membership...
26/11/2025
SVG Sit-Down: Prime Video EP Mike Muriano Previews Massive Black Friday Slate Fe...