Macro Photography
#Focus stacking (also known as focal plane merging and z-stacking[1] or focus blending) is a digital image processing technique which combines multiple images taken at different focus distances to give a resulting image with a greater depth of field (DOF) than any of the individual source images. Focus stacking can be used in any situation where individual images have a very shallow depth of field; #macro photography and optical microscopy are two typical examples.
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Technique
The starting point for focus stacking is a series of images captured at different focal depths; in each image different areas of the sample will be in focus. While none of these images has the sample entirely in focus they collectively contain all the data required to generate an image which has all parts of the sample in focus. In-focus regions of each image may be detected automatically, for example via edge detection or Fourier analysis, or selected manually. The in-focus patches are then blended together to generate the final image.
This processing is also called z-stacking, focal plane merging (or zedification in French).
