update with method for Spatrasters

image.ContourDetector/DESCRIPTION

@@ -9,7 +9,7 @@ Authors@R: c(
     person("BNOSAC", role = "cph", comment = "R wrapper"), 
     person("Rafael Grompone von Gioi", role = c("ctb", "cph"), email = "[email protected]", comment = "src/smooth_contours"), 
     person("Gregory Randall", role = c("ctb", "cph"), email = "[email protected]", comment = "src/smooth_contours"),
-    person("Niccolò Marchi", role = "ctb", email = "niccolo.marchi@unipd.it"))
+    person("Niccolò Marchi", role = "ctb", email = "sciurusurbanus@hotmail.it"))
 Encoding: UTF-8
 License: AGPL-3
 Version: 0.1.1
@@ -19,5 +19,7 @@ LinkingTo: Rcpp
 Suggests:
     pixmap,
     magick,
-    raster
+    raster,
+    sf,
+    terra
 RoxygenNote: 7.1.1

image.ContourDetector/NAMESPACE

@@ -1,6 +1,7 @@
 # Generated by roxygen2: do not edit by hand
 
 S3method(image_contour_detector,RasterLayer)
+S3method(image_contour_detector,SpatRaster)
 S3method(image_contour_detector,matrix)
 S3method(plot,cld)
 S3method(print,cld)

image.ContourDetector/R/contour_detector.R

@@ -11,7 +11,7 @@
 #' an efficient algorithm is derived producing sub-pixel contours.
 #' @param x a matrix of image pixel values in the 0-255 range.
 #' @param Q numeric value with the pixel quantization step
-#' @param ... further arguments, not used yet
+#' @param ... further arguments passed on to \code{image_contour_detector.matrix}, \code{\link{image_contour_detector.RasterLayer}} or \code{\link{image_contour_detector.SpatRaster}}.
 #' @return an object of class cld which is a list with the following elements
 #' \itemize{
 #'  \item{curves: }{The number of contour lines found}
@@ -61,26 +61,6 @@
 #' \}
 #' # End of main if statement running only if the required packages are installed
 #' }
-#' 
-#' ##
-#' ##  working with a RasterLayer
-#' ##
-#' \dontshow{
-#' if(require(raster))
-#' \{
-#' }
-#' \donttest{
-#' library(raster)
-#' x   <- raster(system.file("extdata", "landscape.tif", package="image.ContourDetector"))
-#' 
-#' contourlines <- image_contour_detector(x)
-#' image(x)
-#' plot(contourlines, add = TRUE, col = "blue", lwd = 10)
-#' }
-#' \dontshow{
-#' \}
-#' # End of main if statement running only if the required packages are installed
-#' }
 image_contour_detector <- function(x, Q=2.0, ...){
   UseMethod("image_contour_detector")
 }
@@ -103,25 +83,130 @@ image_contour_detector.matrix <- function(x, Q=2.0, ...){
   return(contourlines)
 }
 
+#' @title Unsupervised Smooth Contour Lines Detection for RasterLayer objects
+#' @description Unsupervised Smooth Contour Detection
+#' @param x a RasterLayer object
+#' @param Q numeric value with the pixel quantization step
+#' @param as_sf Boolean. Set to TRUE to export lines as sf spatial objects
+#' @param ... further arguments passed on to \code{image_contour_detector.matrix}
+#' @return
+#' In case \code{as_sf} is \code{FALSE}: an object of class cld which as described in \code{\link{image_contour_detector}}\cr
+#' In case \code{as_sf} is \code{TRUE}: an object of class sf containing the detected lines, a curve ID and its length (in the same units as the SpatRaster's CRS)
+#' @seealso \code{\link{image_contour_detector}}
 #' @export
-image_contour_detector.RasterLayer <- function(x, Q=2.0, ...){
+image_contour_detector.RasterLayer <- function(x, Q=2.0, as_sf=FALSE, ...){
   requireNamespace("raster")
   minX = raster::extent(x)[1]
   minY = raster::extent(x)[3]  
   resol = raster::res(x)[1]  
-  x = raster::as.matrix(x)
+  xmat = raster::as.matrix(x)
 
-  if( anyNA(x) ){
-    x[is.na(x)] = 0
+  if( anyNA(xmat) ){
+    x[is.na(xmat)] = 0
     warning("NA values found and set to 0") }
 
-  contourlines = image_contour_detector.matrix(x, Q=Q)
+  contourlines = image_contour_detector.matrix( xmat, Q=Q )
 
   contourlines$data$x = contourlines$data$x * resol + minX
   contourlines$data$y = contourlines$data$y * resol + minY
+
+  # export object as sf
+  if(isTRUE(as_sf)){
+    requireNamespace("sf")
+
+    contourlines <- contourlines$data
+    contourlines = sf::st_as_sf( contourlines, coords = c("x", "y"), crs = sf::st_crs(x) )
+
+    out = list()
+
+    for( i in unique(contourlines$curve) ){
+      ss = subset(contourlines, curve == i )
+      ss = sf::st_combine(ss)      
+      out[[length(out)+1]] = sf::st_cast( sf::st_sf(ss), "LINESTRING")
+    }
+
+    contourlines = do.call(rbind,out)    
+    contourlines$curve_ID = 1:nrow(contourlines)
+    contourlines$length = round( sf::st_length(contourlines), 3)
+  }
+
   return(contourlines)
 }
 
+#' @title Unsupervised Smooth Contour Lines Detection for SpatRaster objects
+#' @param x a SpatRaster object
+#' @param Q numeric value with the pixel quantization step
+#' @param as_sf Boolean. Set to TRUE to export lines as sf spatial objects
+#' @param ... further arguments passed on to \code{image_contour_detector.matrix}
+#' @return
+#' In case \code{as_sf} is \code{FALSE}: an object of class cld which as described in \code{\link{image_contour_detector}}\cr
+#' In case \code{as_sf} is \code{TRUE}: an object of class sf containing the detected lines, a curve ID and its length (in the same units as the SpatRaster's CRS)
+#' @seealso \code{\link{image_contour_detector}}
+#' @export
+#' @examples 
+#' \dontshow{
+#' if(require(terra) && require(sf))
+#' \{
+#' }
+#' \donttest{
+#' library(terra)
+#' x   <- rast(system.file("extdata", "landscape.tif", package="image.ContourDetector"))
+#' 
+#' contourlines <- image_contour_detector(x)
+#' plot(x)
+#' plot(contourlines, add = TRUE, col = "blue", lwd = 10)
+#' 
+#' contourlines <- image_contour_detector(x, as_sf = TRUE)
+#' }
+#' \dontshow{
+#' \}
+#' # End of main if statement running only if the required packages are installed
+#' }
+image_contour_detector.SpatRaster <- function(x, Q=2.0, as_sf=FALSE, ...){
+  requireNamespace("terra")
+  minX = terra::ext(x)[1]
+  minY = terra::ext(x)[3]  
+  resol = terra::res(x)[1]  
+  xmat = terra::as.matrix(x, wide=TRUE)
+
+  if(anyNA(xmat)){
+    xmat[is.na(xmat)] = 0
+    warning("NA values found and set to 0") 
+  }
+
+  contourlines = image_contour_detector.matrix( xmat, Q=Q )
+
+  contourlines$data$x = contourlines$data$x * resol + minX
+  contourlines$data$y = contourlines$data$y * resol + minY
+
+  # export object as sf
+  if(isTRUE(as_sf)){
+    requireNamespace("sf")
+
+  # contourlines <- contourlines$data %>%
+  # sf::st_as_sf(coords = c("x", "y"), crs = sf::st_crs(x) ) %>%
+  # dplyr::group_by( curve ) %>%
+  # dplyr::summarize(do_union=FALSE) %>%
+  # sf::st_cast("LINESTRING")
+
+    contourlines <- contourlines$data
+    contourlines = sf::st_as_sf( contourlines, coords = c("x", "y"), crs = sf::st_crs(x) )
+
+    out = list()
+
+    for( i in unique(contourlines$curve) ){
+      ss = subset(contourlines, curve == i )
+      ss = sf::st_combine(ss)      
+      out[[length(out)+1]] = sf::st_cast( sf::st_sf(ss), "LINESTRING")
+    }
+
+    contourlines = do.call(rbind,out)    
+    contourlines$curve_ID = 1:nrow(contourlines)
+    contourlines$length = round( sf::st_length(contourlines), 3)
+  }  
+  return(contourlines)
+}
+
 
 #' @export
 print.cld <- function(x, ...){

image.LineSegmentDetector/DESCRIPTION

@@ -7,13 +7,17 @@ Maintainer: Jan Wijffels <[email protected]>
 Authors@R: c(
     person("Jan", "Wijffels", role = c("aut", "cre", "cph"), email = "[email protected]", comment = "R wrapper"), 
     person("BNOSAC", role = "cph", comment = "R wrapper"), 
-    person("Rafael Grompone von Gioi", role = c("ctb", "cph"), email = "[email protected]", comment = "src/lsd"))
+    person("Rafael Grompone von Gioi", role = c("ctb", "cph"), email = "[email protected]", comment = "src/lsd"),
+    person("Niccolò Marchi", role = "ctb", email = "[email protected]"))
+Encoding: UTF-8
 License: AGPL-3
 Version: 0.1.0
 URL: https://github.com/bnosac/image
 Imports: Rcpp (>= 0.12.8), sp
 LinkingTo: Rcpp
 Suggests:
     pixmap,
-    magick
+    magick,
+    sf,
+    terra
 RoxygenNote: 7.1.0