Misplaced Pages

#625374

37-571: HDRI may stand for: High dynamic range imaging Hot direct reduced iron , a form of iron Topics referred to by the same term [REDACTED] This disambiguation page lists articles associated with the title HDRI . If an internal link led you here, you may wish to change the link to point directly to the intended article. Retrieved from " https://en.wikipedia.org/w/index.php?title=HDRI&oldid=1021571672 " Category : Disambiguation pages Hidden categories: Short description

74-651: A 3D object into a real environment requires the light probe data to provide realistic lighting solutions. In gaming applications, Riven: The Sequel to Myst in 1997 used an HDRI postprocessing shader directly based on Spencer's paper. After E3 2003, Valve released a demo movie of their Source engine rendering a cityscape in a high dynamic range. The term was not commonly used again until E3 2004, where it gained much more attention when Epic Games showcased Unreal Engine 3 and Valve announced Half-Life 2: Lost Coast in 2005, coupled with open-source engines such as OGRE 3D and open-source games like Nexuiz . One of

111-441: A decade, held back by limited computing power, storage, and capture methods. Not until recently has the technology to put HDRI into practical use been developed. In 1990, Nakame, et al. , presented a lighting model for driving simulators that highlighted the need for high-dynamic-range processing in realistic simulations. In 1995, Greg Spencer presented Physically-based glare effects for digital images at SIGGRAPH , providing

148-513: A fraction of the contrast ratio found in the real world, and these are usually measured under ideal conditions. The simultaneous contrast of real content under normal viewing conditions is significantly lower. Some increase in dynamic range in LCD monitors can be achieved by automatically reducing the backlight for dark scenes. For example, LG calls this technology "Digital Fine Contrast"; Samsung describes it as "dynamic contrast ratio". Another technique

185-407: A higher dynamic range, and legacy movies can be converted even if manual intervention will be needed for some frames (as when black-and-white films are converted to color). Also, special effects, especially those that mix real and synthetic footage, require both HDR shooting and rendering . HDR video is also needed in applications that demand high accuracy for capturing temporal aspects of changes in

222-479: A higher dynamic range, they must be tone mapped in order to reduce that dynamic range. High-dynamic-range formats for image and video files are able to store more dynamic range than traditional 8-bit gamma formats. These formats include: OpenEXR was created in 1999 by Industrial Light & Magic (ILM) and released in 2003 as an open source software library . OpenEXR is used for film and television production. Academy Color Encoding System (ACES)

259-472: A lower dynamic range that matches the capabilities of the desired display device. Typically, the mapping is non-linear – it preserves enough range for dark colors and gradually limits the dynamic range for bright colors. This technique often produces visually appealing images with good overall detail and contrast. Various tone mapping operators exist, ranging from simple real-time methods used in computer games to more sophisticated techniques that attempt to imitate

296-399: A new version of DirectX . DirectX 9.0 introduced Shader Model 2.0, which offered one of the necessary components to enable rendering of high-dynamic-range images: lighting precision was not limited to just 8-bits. Although 8-bits was the minimum in applications, programmers could choose up to a maximum of 24 bits for lighting precision. However, all calculations were still integer-based. One of

333-532: A quantitative model for flare and blooming in the human eye. In 1997, Paul Debevec presented Recovering high dynamic range radiance maps from photographs at SIGGRAPH, and the following year presented Rendering synthetic objects into real scenes . These two papers laid the framework for creating HDR light probes of a location, and then using this probe to light a rendered scene. HDRI and HDRL (high-dynamic-range image-based lighting ) have, ever since, been used in many situations in 3D scenes in which inserting

370-437: A sensor for 30fps video will give out 60fps with the odd frames at a short exposure time and the even frames at a longer exposure time. Modern CMOS image sensors can often capture high dynamic range images from a single exposure. This reduces the need to use the multi-exposure HDR capture technique. High dynamic range images are used in extreme dynamic range applications like welding or automotive work. In security cameras

407-626: A side note, when referred to as Shader Model 3.0 HDR, HDRR is really done by FP16 blending. FP16 blending is not part of Shader Model 3.0, but is supported mostly by cards also capable of Shader Model 3.0 (exceptions include the GeForce 6200 series). FP16 blending can be used as a faster way to render HDR in video games. Shader Model 4.0 is a feature of DirectX 10, which has been released with Windows Vista. Shader Model 4.0 allows 128-bit HDR rendering, as opposed to 64-bit HDR in Shader Model 3.0 (although this

SECTION 10

#1732884701626

444-524: A variety of related display and video technologies enabling visualization of HDR content. In April 2007, BrightSide Technologies was acquired by Dolby Laboratories . OLED displays have high contrast. MiniLED improves contrast. In the 1970s and 1980s, Steve Mann invented the Generation-1 and Generation-2 "Digital Eye Glass" as a vision aid to help people see better with some versions being built into welding helmets for HDR vision. In Audio,

481-554: A very high dynamic contrast ratio , around 1,000,000:1. Adaptation is achieved in part through adjustments of the iris and slow chemical changes, which take some time (e.g. the delay in being able to see when switching from bright lighting to pitch darkness). At any given time, the eye's static range is smaller, around 10,000:1. However, this is still higher than the static range of most display technology. Although many manufacturers claim very high numbers, plasma displays , liquid-crystal displays , and CRT displays can deliver only

518-527: Is a large amount of variation in light levels within a scene or an image. The dynamic range refers to the range of luminosity between the brightest area and the darkest area of that scene or image. High dynamic range imaging ( HDRI ) refers to the set of imaging technologies and techniques that allow the dynamic range of images or videos to be increased. It covers the acquisition, creation, storage, distribution and display of images and videos. Modern movies have often been filmed with cameras featuring

555-423: Is a set of techniques used in audio recording and communication to put high-dynamic-range material through channels or media of lower dynamic range. Optionally, dynamic range expansion is used to restore the original high dynamic range on playback. In radio, high dynamic range is important especially when there are potentially interfering signals. Measures such as spurious-free dynamic range are used to quantify

592-428: Is different from Wikidata All article disambiguation pages All disambiguation pages High-dynamic-range imaging The term is often used in discussing the dynamic ranges of images , videos , audio or radio . It may also apply to the means of recording, processing, and reproducing such signals including analog and digitized signals . In this context, the term high dynamic range means there

629-457: Is most visible on point light sources because of their small visual angle. Typical display devices cannot display light as bright as the Sun, and ambient room lighting prevents them from displaying true black. Thus HDR rendering systems have to map the full dynamic range of what the eye would see in the rendered situation onto the capabilities of the device. This tone mapping is done relative to what

666-595: Is preserved in optical phenomena such as reflections and refractions , as well as transparent materials such as glass. In LDR rendering, very bright light sources in a scene (such as the sun) are capped at 1.0. When this light is reflected the result must then be less than or equal to 1.0. However, in HDR rendering, very bright light sources can exceed the 1.0 brightness to simulate their actual values. This allows reflections off surfaces to maintain realistic brightness for bright light sources. The human eye can perceive scenes with

703-417: Is the rendering of computer graphics scenes by using lighting calculations done in high dynamic range (HDR). This allows preservation of details that may be lost due to limiting contrast ratios . Video games and computer-generated movies and special effects benefit from this as it creates more realistic scenes than with more simplistic lighting models. Graphics processor company Nvidia summarizes

740-484: Is the result of scattering in the human lens, which human brain interprets as a bright spot in a scene. For example, a bright light in the background will appear to bleed over onto objects in the foreground. This can be used to create an illusion to make the bright spot appear to be brighter than it really is. Flare is the diffraction of light in the human lens, resulting in "rays" of light emanating from small light sources, and can also result in some chromatic effects. It

777-412: Is to have an array of brighter and darker LED backlights, for example with systems developed by BrightSide Technologies. OLED displays have better dynamic range capabilities than LCDs, similar to plasma but with lower power consumption. Rec. 709 defines the color space for HDTV , and Rec. 2020 defines a larger but still incomplete color space for ultra-high-definition television . Light blooming

SECTION 20

#1732884701626

814-449: Is useful to have the extended accuracy and range of 16 bit integer or 16 bit floating point formats. This is useful irrespective of the aforementioned limitations in some hardware. Complex shader effects began their days with the release of Shader Model 1.0 with DirectX 8. Shader Model 1.0 illuminated 3D worlds with what is called standard lighting. Standard lighting, however, had two problems: On December 24, 2002, Microsoft released

851-518: The Shader Model 3.0 profile for High-Level Shader Language (HLSL). Shader Model 3.0's lighting precision has a minimum of 32 bits as opposed to 2.0's 8-bit minimum. Also all lighting-precision calculations are now floating-point based . NVIDIA states that contrast ratios using Shader Model 3.0 can be as high as 65535:1 using 32-bit lighting precision. At first, HDRR was only possible on video cards capable of Shader-Model-3.0 effects, but software developers soon added compatibility for Shader Model 2.0. As

888-590: The Ultra HD Alliance announced their certification requirements for an HDR display. The HDR display must have either a peak brightness of over 1000 cd/m and a black level less than 0.05 cd/m (a contrast ratio of at least 20,000:1) or a peak brightness of over 540 cd/m and a black level less than 0.0005 cd/m (a contrast ratio of at least 1,080,000:1). The two options allow for different types of HDR displays such as LCD and OLED . Some options to use HDR transfer functions that better match

925-631: The camera. It consists of capturing multiple frames of the same scene but with different exposures and then combining them into one, resulting into an image with a dynamic range higher than the individually captured frames. Some of the sensors on modern phones and cameras may even combine the two images on-chip. This also allows a wider dynamic range being directly available to the user for display or processing without in-pixel compression. Some cameras designed for use in security applications can capture HDR videos by automatically providing two or more images for each frame, with changing exposure. For example,

962-546: The darkest black that a monitor can produce. Multiple technologies allowed to increase the dynamic range of displays. In May 2003, BrightSide Technologies demonstrated the first HDR display at the Display Week Symposium of the Society for Information Display . The display used an array of individually-controlled LEDs behind a conventional LCD panel in a configuration known as " local dimming ". BrightSide later introduced

999-525: The dynamic range of various system components such as frequency synthesizers. HDR concepts are important in both conventional and software-defined radio design. In many fields, instruments need to have a very high dynamic range. For example, in seismology , HDR accelerometers are needed, as in the ICEARRAY instruments . High-dynamic-range rendering High-dynamic-range rendering ( HDRR or HDR rendering ), also known as high-dynamic-range lighting ,

1036-509: The first graphics cards to support DirectX 9.0 natively was ATI 's Radeon 9700 , though the effect wasn't programmed into games for years afterwards. On August 23, 2003, Microsoft updated DirectX to DirectX 9.0b, which enabled the Pixel Shader 2.x (Extended) profile for ATI's Radeon X series and NVIDIA's GeForce FX series of graphics processing units. On August 9, 2004, Microsoft updated DirectX once more to DirectX 9.0c. This also exposed

1073-456: The human visual system other than a conventional gamma curve include the HLG and perceptual quantizer (PQ). HLG and PQ require a bit depth of 10-bits per sample. The dynamic range of a display refers to range of luminosity the display can reproduce, from the black level to its peak brightness. The contrast of a display refers to the ratio between the luminance of the brightest white and

1110-428: The motivation for HDR in three points: bright things can be really bright, dark things can be really dark, and details can be seen in both. The use of high-dynamic-range imaging (HDRI) in computer graphics was introduced by Greg Ward in 1985 with his open-source Radiance rendering and lighting simulation software which created the first file format to retain a high-dynamic-range image. HDRI languished for more than

1147-708: The perceptual response of the human visual system. Currently HDRR has been prevalent in games , primarily for PCs , Microsoft 's Xbox 360 , and Sony 's PlayStation 3 . It has also been simulated on the PlayStation 2 , GameCube , Xbox and Amiga systems. Sproing Interactive Media has announced that their new Athena game engine for the Wii will support HDRR, adding Wii to the list of systems that support it. In desktop publishing and gaming, color values are often processed several times over. As this includes multiplication and division (which can accumulate rounding errors ), it

HDRI - Misplaced Pages Continue

1184-486: The primary advantages of HDR rendering is that details in a scene with a large contrast ratio are preserved. Without HDR, areas that are too dark are clipped to black and areas that are too bright are clipped to white. These are represented by the hardware as a floating point value of 0.0 and 1.0 for pure black and pure white, respectively. Another aspect of HDR rendering is the addition of perceptual cues which increase apparent brightness. HDR rendering also affects how light

1221-399: The scene. This is important in monitoring of some industrial processes such as welding, in predictive driver assistance systems in automotive industry, in surveillance video systems, and other applications. In photography and videography , a technique, commonly named high dynamic range ( HDR ) allows the dynamic range of photos and videos to be captured beyond the native capability of

1258-593: The term high dynamic range means there is a lot of variation in the levels of the sound. Here, the dynamic range refers to the range between the highest volume and lowest volume of the sound. XDR (audio) is used to provide higher-quality audio when using microphone sound systems or recording onto cassette tapes. HDR Audio is a dynamic mixing technique used in EA Digital Illusions CE Frostbite Engine to allow relatively louder sounds to drown out softer sounds. Dynamic range compression

1295-472: The term used instead of HDR is "wide dynamic range". Because of the nonlinearity of some sensors image artifacts can be common. High-dynamic-range rendering (HDRR) is the real-time rendering and display of virtual environments using a dynamic range of 65,535:1 or higher (used in computer, gaming, and entertainment technology). The technologies used to store, transmit, display and print images have limited dynamic range. When captured or created images have

1332-443: The virtual scene camera sees, combined with several full screen effects , e.g. to simulate dust in the air which is lit by direct sunlight in a dark cavern, or the scattering in the eye. Tone mapping and blooming shaders can be used together to help simulate these effects. Tone mapping, in the context of graphics rendering, is a technique used to map colors from high dynamic range (in which lighting calculations are performed) to

1369-629: Was created by the Academy of Motion Picture Arts and Sciences and released in December 2014. ACES is a complete color and file management system that works with almost any professional workflow and it supports both HDR and wide color gamut . High dynamic range (HDR) is also the common name of a technology allowing to transmit high dynamic range videos and images to compatible displays. That technology also improves other aspects of transmitted images, such as color gamut . In this context, On January 4, 2016,

#625374