autocrop(im, color = color.at(im, 1, 1), axes = "zyx")

#Add pointless padding
padded <- pad(boats,30,"xy")
plot(padded)
#Remove padding
autocrop(padded) %>% plot
#You can specify the colour if needs be
autocrop(padded,"black") %>% plot
#autocrop has a zero-tolerance policy: if a pixel value is slightly different from the one you gave
#the pixel won't get cropped. A fix is to do a bucket fill first
padded <- isoblur(padded,10)
autocrop(padded) %>% plot
padded2 <- bucketfill(padded,1,1,col=c(0,0,0),sigma=.1)
autocrop(padded2) %>% plot