Transform image intensities based on histogram mapping.

Apply B-spline 1-D maps to an input image for intensity warping.

histogramWarpImageIntensities(
  image,
  breakPoints = c(0.25, 0.5, 0.75),
  displacements = NULL,
  clampEndPoints = c(FALSE, FALSE),
  sdDisplacements = 0.05,
  transformDomainSize = 20
)

Arguments

image	input image.
breakPoints	parametric points at which the intensity transform displacements are specified between 0, 1. Alternatively, a single number can be given and the sequence is linearly spaced in 0, 1.
displacements	displacements to define intensity warping. Length must be equal to the breakPoints. Alternatively, if NULL random displacements are chosen (random normal: mean = 0, sd = sdDisplacements).
clampEndPoints	specify non-zero intensity change at the ends of the histogram.
sdDisplacements	characterize the randomness of the intensity displacement.
transformDomainSize	Defines the sampling resolution of the B-spline warping.

Value

warped intensity image

Author

Tustison NJ

Examples

library( ANTsR )
image <- antsImageRead( getANTsRData( "r16" ) )
transformedImage <- histogramWarpImageIntensities( image, transformDomainSize = 10 )
rm(image); gc()
#>           used  (Mb) gc trigger  (Mb) limit (Mb) max used  (Mb)
#> Ncells 2550818 136.3    4570014 244.1         NA  4570014 244.1
#> Vcells 4504643  34.4   12255594  93.6      65536 12254504  93.5
rm(transformedImage); gc()
#>           used  (Mb) gc trigger  (Mb) limit (Mb) max used  (Mb)
#> Ncells 2550203 136.2    4570014 244.1         NA  4570014 244.1
#> Vcells 4503654  34.4   12255594  93.6      65536 12254504  93.5