R/convertLABToRGB.R

In CRImage: CRImage a package to classify cells and calculate tumour cellularity

convertLABToRGB <-
function(imgLAB){
	message("convert LAB to RGB")
	labToLMS1=matrix(c(1,1,1,1,1,-2,1,-1,0),c(3,3))
	labToLMS2=matrix(c(sqrt(3)/3,0,0,0,sqrt(6)/6,0,0,0,sqrt(2)/2),c(3,3))
#print(imgLAB)
	LAB=rbind(as.vector(imgLAB[,,1]),as.vector(imgLAB[,,2]),as.vector(imgLAB[,,3]))
	LMS=labToLMS1 %*% labToLMS2 %*% LAB
	LMS=LMS
	lmsToRGB=matrix(c(4.4679,-1.2186,0.0497,-3.5873,2.3809,-0.2439,0.1193,-0.1624,1.2045),c(3,3))
	RGB=lmsToRGB %*% LMS
	imgRGB=imgLAB
	imgRGB[,,1]=array(RGB[1,],dim(imgLAB[,,1]))
	imgRGB[,,2]=array(RGB[2,],dim(imgLAB[,,1]))
	imgRGB[,,3]=array(RGB[3,],dim(imgLAB[,,1]))
	imgRGB/255
	
}