imagefluency (version 0.2.5)

rgb2gray: RGB to Gray Conversion

Description

rgb2gray transforms colors from RGB space (red/green/blue) into an matrix of grayscale values.

Usage

rgb2gray(img)

Value

A matrix of grayscale values.

Arguments

img

3-dimensional array of numeric or integer values

Details

The function takes a 3-dimensional array of numeric or integer values as input (img) and returns a matrix of grayscale values as output. The grayscale values are computed as GRAY = 0.2989 * RED + 0.5870 * GREEN + 0.1140 * BLUE. If the array has a fourth dimension (i.e., alpha channel), the fourth dimension is ignored.

Examples

# construct a sample RGB image as array of random integers
imgRed <- matrix(runif(100, min = 0, max = 255), 10, 10)
imgGreen <- matrix(runif(100, min = 0, max = 255), 10, 10)
imgBlue <- matrix(runif(100, min = 0, max = 255), 10, 10)
imgColor <- array(c(imgRed, imgGreen, imgBlue), dim = c(10, 10, 3))

# convert to gray
img <- rgb2gray(imgColor)