High Dynamic Range (HDR) Image and Photography is a digital image that can save the naturally occurring differences in luminance detail. Conventional digital images that are not in a position to be referred to as low dynamic range images or LDR images. High Dynamic Range images can be taken by special cameras, some computer graphics software or from an exposure series reconstructed from LDR photos. So far there are only a few output devices that are capable to display HDR images. On conventional screens and media, High Dynamic Range (images can not be represented directly, but must be converted to LDR images. This process is called dynamic range compression.
Working principle of High Dynamic Range images and High Dynamic Range photography
Most digital images uses only 256 levels (8 bits ) each of red, green and blue color channels. This color range is often not sufficient to render the scenes like in real. Higher color depths are usually barely used because screens and print media for their representation are not capable to display or print them.
The points of a camera from visual environment typically has a dynamic range (ratio of maximum and minimum luminance ) of 10,000:1. The dynamic range is still significantly larger when a light source is directly visible. Unit for specifying the High Dynamic Range is deciBel (dB).
On the High Dynamic Range Imaging image files are produced with a dynamic range that can detect the naturally occurring brightness. In High Dynamic Range images, the pixel values stand in a proportional relationship to the actual luminance. Although still almost all screens have low brightness range, i.e. they are unable to display High Dynamic Range images.
Usage of High Dynamic Range images
- Digital Photography
- Digital cinema
- Virtual reality
- Monitoring systems
- Health Science
You can download this High Dynamic Range Image Wallpaper from our wallpaper section.
The most common application of High Dynamic Range photography is in Health Science : In endoscopy, the principle is to use smallest possible image sensors to deliver high quality images even in low light, that is achieved by using High Dynamic Range Cameras.
Exposure Blending and High Dynamic Range Image
The beautiful images we generally see of different so called High Dynamic Range Image, like a surreal landscape, is often a pseudo-HDR, not High Dynamic Range Image. A High Dynamic Range (HDR) camera can cost around $ 60,000 output the file as JPEG-HDR or other formats. Using the conventional digital cameras High Dynamic Range images are somewhat created by using an exposure series of photographs – that is normal images from least exposure to highest exposure is taken and then processed to create somewhat High Dynamic Range images.