plotOF: Plot Optical Flow Arrays

In swarm-lab/Rvision: Computer Vision Library for R

Plot Optical Flow Arrays

Description

Plotting method for Image objects produced by the farneback function.

Usage

plotOF(
  of,
  gridsize = c(25, 25),
  thresh = 0,
  add = TRUE,
  arrow.ex = 0.05,
  xpd = TRUE,
  ...
)

Arguments

of	An Image produced by the farneback function.
gridsize	A 2-element vector indicating the number of optical flow vectors to plot in each x-y dimension (default: c(25, 25)). Alternatively, a numeric value that will be used for both dimensions.
thresh	The minimal length of optical flow vectors that should be plotted (default: 0).
add	A logical indicating whether to plot the vector field over an existing plot (default: FALSE).
arrow.ex	Controls the length of the arrows. The length is in terms of the fraction of the shorter axis in the plot. So with a default of .05, 20 arrows of maximum length can line up end to end along the shorter axis.
xpd	If true does not clip arrows to fit inside the plot region, default is not to clip.
...	Graphics arguments passed to the arrows function that can change the color or arrow sizes. See arrows help for details.

Author(s)

Simon Garnier, [e-mail]

See Also

farneback, arrows

Examples

balloon <- video(system.file("sample_vid/Balloon.mp4", package = "Rvision"))
balloon1 <- readFrame(balloon, 1)
balloon2 <- readFrame(balloon, 2)
changeColorSpace(balloon1, "GRAY", "self")
changeColorSpace(balloon2, "GRAY", "self")
of <- farneback(balloon1, balloon2)
plot(of)
plotOF(of, length = 0.05)

swarm-lab/Rvision documentation built on Feb. 7, 2024, 4:59 a.m.