Merge pull request #91 from swarm-lab/develop

Add affine transform matrix computation and string argument for streams.

NAMESPACE

@@ -145,6 +145,7 @@ export(fps)
 export(frame)
 export(full)
 export(gaussianBlur)
+export(getAffineTransform)
 export(getGaborKernel)
 export(getPerspectiveTransform)
 export(getProp)

R/StreamClass.R

@@ -29,9 +29,18 @@
 #' @description Function for creating \code{\link{Stream}} objects from video
 #'  streams.
 #'
-#' @param index An integer value corresponding to the index of the camera to
-#'  read a stream from (default: 0; 0 is usually the default webcam on most
-#'  computers).
+#' @param ... Either:
+#'  \itemize{
+#'    \item{index: }{An integer value corresponding to the index of the camera
+#'      to read a stream from (default: 0; 0 is usually the default webcam on
+#'      most computers). Or...}
+#'    \item{stream_string: }{...a character string corresponfing to the URL of
+#'      video stream (eg. protocol://host:port/script_name?script_params|auth)
+#'      or a GStreamer pipeline string in gst-launch tool format if GStreamer is
+#'      used as backend API. Note that each video stream or IP camera feed has
+#'      its own URL scheme. Please refer to the documentation of source stream
+#'      to know the right URL format.}
+#'  }
 #'
 #' @param api A character string corresponding to the API to use for reading the
 #'  stream from the camera (see Note; default: "ANY").
@@ -77,8 +86,17 @@
 #' }
 #'
 #' @export
-stream <- function(index = 0, api = "ANY") {
-  new(Stream, index = index, api = api)
+stream <- function(..., api = "ANY") {
+  args <- list(...)
+
+  if (!inherits(args[[1]], "character"))
+    args[[1]] <- as.integer(args[[1]])
+
+  if (length(args) > 1)
+    if (inherits(args[[2]], "character"))
+      api <- args[[2]]
+
+  new(Stream, args[[1]], api = api)
 }
 
 

R/feature.R

@@ -366,7 +366,7 @@ ORBkeypoints <- function(image, mask = NULL, n_features = 500, scale_factor = 1.
 
   st <- switch(score_type,
                "HARRIS" = 0,
-               "FAST" = 0,
+               "FAST" = 1,
                stop("Invalid score type.")
   )
 

R/transform.R

@@ -453,6 +453,51 @@ getPerspectiveTransform <- function(from, to, from_dim, to_dim = from_dim) {
 }
 
 
+#' @title Affine Transform
+#'
+#' @description \code{getAffineTransform} computes the matrix of an affine
+#'  transform from 4 pairs of corresponding points in a source and destination
+#'  image.
+#'
+#' @param from A 4x2 matrix indicating the location (x, y) of 4 points in the
+#'  source image.
+#'
+#' @param to A 4x2 matrix indicating the location (x, y) of 4 points in the
+#'  destination image. The order of the points must correspond to the order in
+#'  \code{from}.
+#'
+#' @param from_dim A vector which first two elements indicate the number of rows
+#'  and columns of the source image.
+#'
+#' @param to_dim A vector which first two elements indicate the number of rows
+#'  and columns of the destination image. If not specified, \code{from_dim} will
+#'  be used as a default.
+#'
+#' @return A 3x3 matrix.
+#'
+#' @author Simon Garnier, \email{garnier@@njit.edu}
+#'
+#' @seealso \code{\link{warpAffine}}
+#'
+#' @examples
+#' from <- matrix(c(1, 1, 2, 5, 6, 5, 5, 1), nrow = 4, byrow = TRUE)
+#' to <- matrix(c(1, 1, 1, 5, 5, 5, 5, 1), nrow = 4, byrow = TRUE)
+#' getAffineTransform(from, to, c(1080, 1920), c(1080, 1920))
+#'
+#' @export
+getAffineTransform <- function(from, to, from_dim, to_dim = from_dim) {
+  if (any(dim(from) != c(4, 2)) | any(dim(to) != c(4, 2)))
+    stop("'from' and 'to' must be 4x2 matrices.")
+
+  from[, 1] <- from[, 1] - 1
+  from[, 2] <- -from[, 2] + from_dim[1]
+  to[, 1] <- to[, 1] - 1
+  to[, 2] <- -to[, 2] + from_dim[1] - (from_dim[1] - to_dim[1])
+
+  `_getAffineTransform`(from, to)
+}
+
+
 #' @title Perspective Transformation
 #'
 #' @description \code{warpPerspective} applies a perspective transformation to

docs/pkgdown.yml

@@ -9,7 +9,7 @@ articles:
   z5_gpu: z5_gpu.html
   z6_queue: z6_queue.html
   z7_stack: z7_stack.html
-last_built: 2023-08-08T12:51Z
+last_built: 2023-08-09T18:21Z
 urls:
   reference: https://swarm-lab.github.io/Rvision/reference
   article: https://swarm-lab.github.io/Rvision/articles

docs/sitemap.xml

@@ -279,6 +279,9 @@
   <url>
     <loc>https://swarm-lab.github.io/Rvision/reference/gaussianBlur.html</loc>
   </url>
+  <url>
+    <loc>https://swarm-lab.github.io/Rvision/reference/getAffineTransform.html</loc>
+  </url>
   <url>
     <loc>https://swarm-lab.github.io/Rvision/reference/getGaborKernel.html</loc>
   </url>

src/Stream.h

@@ -1,7 +1,9 @@
 class Stream : public Capture {
 public:
   Stream(int index, std::string api);
+  Stream(std::string stream_string, std::string api);
   bool open(int index, std::string api);
+  bool openStr(std::string stream_string, std::string api);
 
 private:
 };
@@ -12,9 +14,22 @@ Stream::Stream(int index, std::string api) {
   }
 }
 
+Stream::Stream(std::string stream_string, std::string api) {
+  if (!this->cap.open(stream_string, getAPIId(api))) {
+    Rcpp::stop("Could not open the stream.");
+  }
+}
+
 bool Stream::open(int index, std::string api) {
   if (!this->cap.open(index, getAPIId(api)))
     Rcpp::stop("Could not open the stream.");
 
   return true;
 }
+
+bool Stream::openStr(std::string stream_string, std::string api) {
+  if (!this->cap.open(stream_string, getAPIId(api)))
+    Rcpp::stop("Could not open the stream.");
+
+  return true;
+}