High Dynamic Range Video

High dynamic range video (HDRv) is the next step in digital imaging (What is HDR?). By capturing the full dynamic range in a scene HDRv enables a wide range of new imaging applications. At the HDRv repository, we display bleeding edge HDR technology and the results from our research in computer graphics, vision and image processing.

The video displays examples from our HDRv gallery. At the Gallery & Resources page, we make available HDRv footage and software for download, and display a number of example sequences captured using the HDRv imaging system. The sequences are captured in different environments and displayed in tone mapped form, false colored to display the dynamic range in the scene, and as HDR images that can be downloaded or viewed directly in our online WebGL HDR viewer (requires a WebGL enabled web browser).

HDRv capture

The HDRv sequences are captured using an HDRv imaging system developed in a collaboration between the camera manufacturer SpheronVR and the Computer Graphics and Image Processing group at Linköping University in Sweden.

The 4 Mpixel HDRv camera.

The camera captures HDR images with a resolution of 2336x1752 pixels at up to 30 fps with a dynamic range of over 24 f-stops. The high bandwidth HDR data stream can be viewed in real time through GPU processing, and is written without compression to file on an external storage unit. Both the camera and storage unit runs on battery for up to three hours of sustained capture.

What is High Dynamic Range?

The dynamic range (Wikipedia) of a camera is the ratio between the largest and smallest possible light intensities that the camera can capture. If the intensity is too small, the pixel value will be black. If the intensity is to large, the pixel will be saturated and be encoded as being white.
An ordinary camera exhibits a dynamic range in the order of 1000 : 1 or less, while an ordinary indoor scene usually exhibits a dynamic range of more than 100.000 : 1 or more. An outdoor scene including the sun usually exhibits a dynamic range of up to 10.000.000 : 1 or more. This means that the dynamic range of the ordinary camera cannot capture the full range of light intensities within a single exposure setting. The exposure settings such as exposure time and aperture size controls the amount of light that reaches the sensor. This means that the dynamic range available on the camera can be adjusted to capture a certain range of light intensities.

The images in sequence above are captured with a semi-professional digital SLR camera, where the exposure time has been changed between each frame. From left to right, the exposure time is increased. It is evident that the dynamic range of the camera cannot capture that of the scene, and that the bright background requires very short exposure times while the much darker foreground requires long exposure times.
A high dynamic range (HDR) (Wikipedia) image covers the full dynamic range of the scene and thus captures all its light intensities. In the example above, this means that an HDR image would image both the background and the foreground simultaneosly.
HDR imaging makes it possible to accurately capture and represent the exact lighting conditions (scene radiance) found in the real world scene. In contrast to conventional images, this enables significantly more advanced: display, computer vision and image post processing algorithms, as well as applications such as computer graphics rendering of photo-realistic images of synthetic objects placed into the captured real world scene. Early adopters of HDR imaging are the movie special effects, computer games, and product and architectural visualization industry.