Generates a "dirac" image, i.e. with all values set to 0 except one.

Description

This small utility is useful to examine the impulse response of a filter

Usage

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imdirac(dims, x, y, z = 1, cc = 1)

Arguments

dims

a vector of image dimensions, or an image whose dimensions will be used. If dims has length < 4 some guesswork will be used (see examples and ?as.cimg.array)

x

where to put the dirac (x coordinate)

y

y coordinate

z

z coordinate (default 1)

cc

colour coordinate (default 1)

Value

an image

Author(s)

Simon Barthelme

Examples

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#Explicit settings of all dimensions 
imdirac(c(50,50,1,1),20,20) 
imdirac(c(50,50),20,20) #Implicit
imdirac(c(50,50,3),20,20,cc=2) #RGB
imdirac(c(50,50,7),20,20,z=2) #50x50 video with 7 frames
#Impulse response of the blur filter
imdirac(c(50,50),20,20) %>% isoblur(sigma=2)  %>% plot
#Impulse response of the first-order Deriche filter
imdirac(c(50,50),20,20) %>% deriche(sigma=2,order=1,axis="x")  %>% plot
##NOT RUN, interactive only
##Impulse response of the blur filter in space-time
##resp <- imdirac(c(50,50,100),x=25,y=25,z=50)  %>%  isoblur(16)
###Normalise to 0...255 and play as video
##renorm(resp) %>% play(normalise=FALSE)

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