if(interactive()) {
source <- system.file("extdata", "epi_t2.nii.gz", package="RNiftyReg")
target <- system.file("extdata", "flash_t1.nii.gz", package="RNiftyReg")
aligned <- register_volume(source, target, verbose = FALSE)
source_img <- aligned$source[[1]]
target_img <- aligned$target
aligned_img <- aligned$image
par(mfrow = c(2, 2), mar = c(0.1, 0.1, 3.1, 0.1))
pal <- grDevices::grey.colors(256, alpha = 1)
image(source_img[,,30], asp = 1, axes = FALSE,
col = pal, main = "Source image")
image(target_img[,,64], asp = 1, axes = FALSE,
col = pal, main = "Target image")
image(aligned_img[,,64], asp = 1, axes = FALSE,
col = pal, main = "Aligned image")
# bucket fill and calculate differences
aligned_img[is.nan(aligned_img) | aligned_img <= 1] <- 1
target_img[is.nan(target_img) | aligned_img <= 1] <- 1
diff <- abs(aligned_img / target_img - 1)
image(diff[,,64], asp = 1, axes = FALSE,
col = pal, main = "Percentage Difference")
}
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