Initial Push

#+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++

## a. CLEAN WORKSPACE AND LOAD LIBRARIES ----

#+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++

rm(list=ls())

library(imager)

img <- load.image(file='00_data/RJ_santa.jpeg')

img.gray <- grayscale(img, method = "Luma", drop = TRUE) 

#Edge filter

filter <- as.cimg(function(x,y) sign(x-10),5,5) 

#Convolution vs. correlation 

img.corr <- correlate(img.gray,filter)

bin_image <- round(img.corr/1*max(img.corr),0)

plot(bin_image)

raster <- as.raster(bin_image)

pxl_grid <- expand.grid(x = 1:nrow(raster), y = 1:ncol(raster)) 

out <- transform(pxl_grid, z = raster[as.matrix(pxl_grid)])

unique(out$z)

out$y <- ncol(raster)-(ncol(raster)-out$y+1)

out$x <- nrow(raster)-out$x+1

out.idx1 <- which(out$z %in% c("#000000","#333333"))

smpl.idx1 <- sample(out.idx1,size=60000,replace=FALSE)

out.idx2 <- which(out$z %in% c("#666666"

                               ,"#999999"))

smpl.idx2 <- sample(out.idx2,size=30000,replace=FALSE)

out.idx3 <- which(out$z %in% c("#CCCCCC"))

smpl.idx3 <- sample(out.idx3,size=5000,replace=FALSE)

plot(out[c(smpl.idx1,

           smpl.idx2,

           smpl.idx3

           ),c("y","x")],pch=16,cex=0.1)

out_matrix <- data.frame(out[c(smpl.idx1,smpl.idx2,smpl.idx3),c("y","x")])

out_matrix <- out_matrix[sample.int(nrow(out_matrix),size=nrow(out_matrix),replace=FALSE),]

out_matrix$ID <- 1:nrow(out_matrix)

out_matrix <- out_matrix[,c("ID","y","x")]

rownames(out_matrix) <- NULL

names(out_matrix) <- c("ID","x","y")

write.csv(out_matrix,file="00_data/point_cloud.csv",row.names = FALSE)

 No newline at end of file

Version: 1.0

RestoreWorkspace: Default

SaveWorkspace: Default

AlwaysSaveHistory: Default

EnableCodeIndexing: Yes

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RnwWeave: Sweave

LaTeX: pdfLaTeX