Image Stacking refers to a group of image processing techniques in which multiple images with slight variations are combined to obtain one image of high quality.
Image Stacking can be used to improve an image in several ways, such as
reducing noise and enabling low-light photography,
increasing resolution,
increasing depth of field or
removing unwanted objects.
In addition to the built-in stacking features, Chasys Draw IES is bundled with a powerful image stacking plug-in called MegaStack™ which can easily stack thousands of images using the Image Averaging technique mentioned below.
What is it used for?
The most common image stacking technique is Image Averaging (referred to in some texts as the “shift-and-add” method)
which is used for obtaining high quality images from a number of short exposures with varying image shifts.
It has been used in astronomy for several decades as a form of speckle imaging, and is the basis for the image-stabilization feature on some cameras.
It involves the calculation of “motion vectors”, which describe how a given scene has moved from one image to another.
The images are then shifted back to a common center and added together.
This provides an image with higher resolution (higher signal-to-noise at high spatial frequencies) than a conventional long exposure image.
Another common image stacking technique is Focus Stacking (referred to in some texts as “focal plane merging”,
“z-stacking” or “focus blending”) which is used to combine 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. This is useful in situations where individual images tend to have very shallow depth of field,
such as in macro photography and optical microscopy.
