This function converts from RGB images to grayscale
Usage
grayscale(im, method = "Luma", drop = TRUE)
Value
a grayscale image (spectrum == 1)
Arguments
im
an RGB image
method
either "Luma", in which case a linear approximation to luminance is used, or "XYZ", in which case the image is assumed to be in sRGB color space and CIE luminance is used.
drop
if TRUE returns an image with a single channel, otherwise keep the three channels (default TRUE)
grayscale(boats) %>% plot
#In many pictures, the difference between Luma and XYZ conversion is subtle grayscale(boats,method="XYZ") %>% plot
grayscale(boats,method="XYZ",drop=FALSE) %>% dim