cannyEdges: Canny edge detector

In imager: Image Processing Library Based on 'CImg'

Canny edge detector

Description

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

cannyEdges(im, t1, t2, alpha = 1, sigma = 2)

Arguments

im	input image
t1	threshold for weak edges (if missing, both thresholds are determined automatically)
t2	threshold for strong edges
alpha	threshold adjusment factor (default 1)
sigma	smoothing

Author(s)

Simon Barthelme

Examples

cannyEdges(boats) %>% plot
#Make thresholds less strict
cannyEdges(boats,alpha=.4) %>% plot
#Make thresholds more strict
cannyEdges(boats,alpha=1.4) %>% plot

imager documentation built on May 29, 2024, 1:38 a.m.