edgeDetection {biopixR}

Canny edge detector

Description

Adapted code from the 'imager' cannyEdges function without the usage of 'dplyr' and 'purrr'. If the threshold parameters are missing, they are determined automatically using a k-means heuristic. Use the alpha parameter to adjust the automatic thresholds up or down. The thresholds are returned as attributes. The edge detection is based on a smoothed image gradient with a degree of smoothing set by the sigma parameter.

Usage

edgeDetection(img, t1, t2, alpha = 1, sigma = 2)

Arguments

img

image (import by importImage)

t1

threshold for weak edges (if missing, both thresholds are determined automatically)

t2

threshold for strong edges

alpha

threshold adjustment factor (default 1)

sigma

smoothing (default 2)

Value

Object of class 'cimg', displaying detected edges.

References

https://CRAN.R-project.org/package=imager

Examples

edgeDetection(beads, alpha = 0.5, sigma = 0.5) |> plot()