Question

How does EDF image processing work?

Answer

EDF (extended depth of field) processing works by combining the best focused parts of a number of images taken at different focus levels into a composite image.

To create an EDF image you must scan a region of interest using the multi-layer focus method. This captures each field in the region of interest at multiple focus levels. These images are then used to create the composite EDF image when you create a whole scan image. Refer to Creating Whole Scan Images for Multi-Layer Scans for more information.

For example, the following images of a single field were captured at different focus levels.

Layer 1

Layer 2

Layer 3

Layer 4

Layer 5

Layer 6

Each of the above images shows different parts of the specimen that are in focus and out of focus. EDF software combines the best focused parts into the following composite image.

Composite EDF Image

The composite EDF image above shows everything in the best possible focus based on the multi-layer scan images.

Note
The above composite EDF image was created from many more than six (6) layer images. Only six (6) layers are shown above for the sake of brevity.