Exposure Fusion

The exposure fusion (Exposure Fusion ), exposure blend ( Exposure Blending ), dynamic range increase (Dynamic Range Increase, DRI) or pseudo - HDR are referred to in the digital image processing method to organize captured with different exposure times frames of the same scene ( bracketing ) as a single image combine that are over - and under-exposed areas remain largely avoided and get more details. Exposure Fusion is a pure method of image processing, in which the dynamic range of the image is not increased; the term " dynamic range increase " or "DRI " is therefore misleading.

Demarcation to HDR Photography

Exposure fusion has similar aims as HDR photography (see also HDRI generation of bracketing ), but is technically simpler construction. Does not generate temporary HDR- images, which must then be converted by means of tone mapping back into displayable images. This simplified process is generally faster than generating HDR images, followed by tone mapping and achieved at appropriate method of comparable quality.

Method

In manual exposure fusion, the individual shots of the Bracketing with a standard image-editing program put together, in each case the lightest shades in the image are replaced by the corresponding points from the next darker image, see picture.

Algorithms have been developed that allow the manual method described above can be automated and improved. These automatic methods consist of two steps:

• Step 1: Realize in each image bracketing the correctly exposed image areas.
• Step 2: Combine this image parts to form a whole that then essentially consists of only the correctly exposed image parts of individual drawing files.

Technically closely related to the exposure fusion, the process of the focus is stacking. In Focus stacking another criterion for determining the image to use parts used in step 1, the combination of the individual parts of the image (step 2) is performed but analog.