draw.segments.on.image: Draw contour segments onto a magick image.
In fsbrain: Managing and Visualizing Brain Surface Data

draw.segments.on.image

R Documentation

Draw contour segments onto a magick image.

Description

Draws a set of line segments (as returned by mesh.slice.intersection) onto a magick image. Individual mesh triangles produce small segments, which collectively trace the contour boundary when drawn together.

Usage

draw.segments.on.image(
  img,
  segments,
  slice_axis,
  row_axis,
  col_axis,
  color = "#FF0000",
  lwd = 1,
  coord_scale = 1L
)

Arguments

`img`	a magick image instance (a single 2D slice image).
`segments`	list of 2×2 matrices, each a line segment in 0-based CRS coordinates on the two orthogonal axes.
`slice_axis`	integer, the axis (1,2,3) perpendicular to the slice plane.
`row_axis`	integer, which CRS axis (1, 2, or 3) maps to the image row dimension.
`col_axis`	integer, which CRS axis (1, 2, or 3) maps to the image column dimension.
`color`	character string, the color for the contour lines.
`lwd`	numeric, line width passed to `segments`. Defaults to 1.
`coord_scale`	positive integer, the factor by which the CRS coordinates must be multiplied to map them to image pixel coordinates. Defaults to 1L, which maps coordinates 1:1 to pixels (as is the case when the image is at native resolution). Use larger values when drawing onto a scaled-up image or overlay.