Skip to contents

Convert Curvature Values to Smooth Gradient Colors

Source: R/view_surface.R
curv_cols_smooth.Rd

Maps surface curvature values to a continuous grayscale gradient, producing a FreeSurfer-style sulcal shading that is visually smoother than the binary mapping of curv_cols.

Usage

curv_cols_smooth(
  vals,
  light = "#D4D4D4",
  dark = "#3A3A3A",
  quantiles = c(0.05, 0.95)
)

Arguments

vals

A numeric vector of curvature values for each vertex.

light

Hex color for the lightest shade (gyral crowns). Default "#D4D4D4".

dark

Hex color for the darkest shade (sulcal fundi). Default "#3A3A3A".

quantiles

Length-2 numeric vector of lower and upper quantiles used to clamp extreme values before rescaling. Default c(0.05, 0.95).

Value

A character vector of hex color codes the same length as vals.

Details

Values are clamped to the range defined by quantiles to prevent outliers from washing out the colour map. The clamped values are linearly interpolated between dark (most negative / sulcal) and light (most positive / gyral).

See also

curv_cols, curvature, view_surface

Examples

set.seed(1)
curv <- rnorm(500, sd = 0.1)
cols <- curv_cols_smooth(curv)
head(cols)
#> [1] "#686868" "#8E8E8E" "#5E5E5E" "#D0D0D0" "#959595" "#5F5F5F"