With this function you remove smooth background or correct uneven illumination. The implementation is adapted from the corresponding function in ImageJ and based on the “rolling ball” algorithm (S. Sternberg, “Biomedical Image Processing”, IEEE Computer, January 1983).

Parameters

Parameter

Description

Radius

Here you adjust the radius of the rolling ball in pixels. This value should be at least as large as the radius of the largest object in the image that is not part of the background. Larger values will also work unless the background of the image is too uneven.

Create Background only

If activated, an image which contains the detected background only is created. Use this image to subsequently perform manual corrections of the image background, e.g. using the image calculator function.

Do smoothing beforehand

If activated, a 3 x 3 pixel averaging is performed before analyzing the background. Use this option to ensure that the image data after subtraction will not be below the background.

Light Background

Use this option if your image contains bright background and dark objects.