getSteps {xRing}

Select the Steps of a Calibration Wedge Interactively

Description

Obtain the Grayvalue of Each Step of a Calibration Wedge

Usage

getSteps(im, nSteps = NULL, auto = FALSE, nPixel = 50)

Arguments

im

an image.

nSteps

number of steps of the calibration wedge to obtain grayvalues from.

auto

logical. If TRUE, automatic detection of the steps given a line is carried out. Use with care.

nPixel

gives the line width when 'auto = TRUE'

Value

a numeric vector

Examples

if (interactive()) {
  # read a sample file
  im <- imRead(file = system.file("img", "AFO1046.1200dpi.png", package = "xRing"))

  # display the image
  imDisplay(im)

  # get the grayvalues from the calibration wedge on the film
  steps <- grayvalues <- getSteps(im, 7) # select 7 ROIs
  steps1 <- grayvalues <- getSteps(im, 7, auto = TRUE) # select a single ROI
  cor(steps, steps1)
}