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Blur

The Blur command applies a box (mean) filter to the image. Every pixel is replaced by the average intensity of its surrounding neighbourhood.

When to use

Use Blur as a fast, lightweight noise-reduction step before segmentation. For better edge preservation, consider Gaussian Blur instead.

Parameters

ParameterDescription
Kernel sizeSide length of the averaging kernel in pixels (must be odd; range 3–27)

Kernel size guidance

  • 3–5 — subtle smoothing, preserves fine structure
  • 7–11 — moderate noise reduction for typical fluorescence images
  • 13+ — heavy smoothing; fine structures may be lost

Notes

In image processing, a kernel (convolution matrix) is a small matrix applied to each pixel and its neighbours. A box blur kernel fills every element with 1/N, replacing each pixel with the neighbourhood mean.