imager (version 0.14)

convolve: Convolve image by filter.

Description

The result res of the convolution of an image img by filter flt is defined to be: $res(x,y,z) = sum_{i,j,k} img(x-i,y-j,z-k)*flt(i,j,k)$

Usage

convolve(im, filter, boundary_conditions = TRUE, normalise = FALSE)

Arguments

im

an image

filter

a filter (another image)

boundary_conditions

= the border condition type (0=zero, 1=dirichlet)

normalise

= normalise filter (default FALSE)

See Also

correlate

Examples

#Edge filter
filter <- as.cimg(function(x,y) sign(x-5),10,10)
layout(t(1:2))
#Convolution vs. correlation
correlate(boats,filter) %>% plot(main="Correlation")
convolve(boats,filter) %>% plot(main="Convolution")