High Dynamic Range (HDR) photography is the process of creating images in which the ratio between the maximum and minimum measurable light levels are higher than can normally be achieved during a single photographic exposure. HDR Tone Mapping is the process of transforming HDR photos into normal dynamic range photos, suitable for displaying on a computer monitor, television or for making a hard-copy print.
Essential HDR™ (code name Wukong*) is a revolutionary new HDR tone mapping software. It includes two proprietary tone mapping algorithms: Fast Tone Balancer™, for global tone mapping, and ,Detail Revealer™, for local tone mapping. Both tone mapping algorithms provide superior results and lightning fast performance.
Imaging Luminary's Fast Tone Balancer tone mapping technology is one of the fastest and most effective global tone mapping operators in existence. It analyzes the overall contrast of a scene and calculates the optimal compression curve to apply to it, providing the user with an immediate visualization of their HDR photo.
Imaging Luminary's revolutionary tone mapping technology, Detail Revealer™ , is based on the human visual system's method of coping with high dynamic range scenes. A sophisticated mathematical approach has been applied to the simulation of human perception and, as a result, Detail Revealer successfully brings out the subtle details in a scene by using the same methods by which detail and luminance variations are processed by the human visual system.
Detail Revealer starts with an explicit and detailed definition of the human visual system's method of coping with high dynamic range scenes, formulated as a mathematical optimization problem. This problem is then solved by the application of an advanced and innovative algorithm. This is very different to the way other tone mapping algorithms, such as Fattal02[1], work. The result is greatly improved image quality and speed in comparison with most mainstream HDRI software, which take a heuristic and intuitive approach.
Our Detail Revealer technology has the following advantages:
Detail Revealer's preview result and full size results are almost exactly the same
The preview image is, usually, a smaller version of the image being processed. This size reduction results in changes in local detail data which cause the final output of many local tone mapping systems to differ dramatically from the preview image. This widely reported problem causes a great deal of frustration among photographers who, having spent a lot of time working on an image to fine-tune it to perfection, find that the full image, tone mapped using the same set of parameters, is nothing like they were expecting. The superior algorithm of Detail Revealer does not suffer from this problem, successfully maintaining a high level of consistency between the preview image and the resulting, full tone mapped image.
Detail Revealer does not produce halo or "glowing edge" artifacts.
Because it is based on the human visual system, Detail Revealer's approach to edge detection is able to produce more natural-looking transitions, devoid of the artifacts which plague other systems. Having been able to detect and understand the transition between an object and the background, it can treat the sky and the buildings in this example image completely differently.
Lighting consistency is maintained without sacrificing detail. The result is cleaner and clearer pictures.
In other local tone mappers, to reduce halo or other artifacts, you have to reduce the level of local detail. The result is usually described as "haze". Detail Revealer is a brand new algorithm, using a totally different approach and, as a result, does not suffer from this problem at all.
Detail Revealer does not produce random brightness variations.
As with the human vision system, Detail Revealer's sophisticated artificial intelligence engine can recognize large, bright areas, even when they are fragmented. In this example, the sky is recognized as one entity; so it is processed consistently, despite being split up into myriad smaller areas by the branches of the trees.
Fast, and scales well with dual-core CPUs. Image processing speed is well above two million pixels/second for large images using today's mainstream PCs. You don't have to wait minutes any more!
References:
[1] Raanan Fattal, Dani Lischinski, Michael Werman. "Gradient Domain High Dynamic Range Compression", ACM SIGGRAPH 2002
* Wukong, meaning "aware of emptiness", comes from the playful monkey king in ancient Chinese mythology. He is extremely intelligent, powerful, versatile, and is known for breaking all the rules in the Heavenly Kingdom.
