Test qr scanner

Author: jeroen

NAMESPACE

@@ -31,6 +31,7 @@ export(ocv_stylize)
 export(ocv_version)
 export(ocv_video)
 export(ocv_write)
+export(qr_scanner)
 importFrom(Rcpp,sourceCpp)
 importFrom(magrittr,"%>%")
 useDynLib(opencv)

R/RcppExports.R

@@ -81,8 +81,8 @@ cvmat_display <- function(ptr) {
     invisible(.Call('_opencv_cvmat_display', PACKAGE = 'opencv', ptr))
 }
 
-livestream <- function(filter) {
-    invisible(.Call('_opencv_livestream', PACKAGE = 'opencv', filter))
+livestream <- function(filter, stop_on_result = FALSE) {
+    .Call('_opencv_livestream', PACKAGE = 'opencv', filter, stop_on_result)
 }
 
 data_prefix <- function() {

R/opencv.R

@@ -160,21 +160,13 @@ ocv_display <- function(image){
 #' @export
 #' @rdname opencv
 #' @param filter an R function that takes and returns an opecv image
-ocv_video <- function(filter){
+ocv_video <- function(filter, stop_on_result = FALSE){
   if(!is.function(filter))
     stop("Filter must be a function")
   message("Starting video window (could be behind this window)")
-  livestream(function(image){
-    if(!inherits(image, 'opencv-image'))
-      stop("Image must be opencv-image")
-    out <- filter(image)
-    if(!inherits(out, 'opencv-image'))
-      stop("Output must be opencv-image")
-    return(out)
-  })
+  livestream(filter, stop_on_result)
 }
 
-
 #' @export
 #' @rdname opencv
 ocv_grayscale <- function(image){

R/qr.R

@@ -18,3 +18,15 @@ ocv_qrtext <- function(image){
 ocv_qrmask <- function(image){
   cvmat_qrmask(image)
 }
+
+#' @export
+#' @rdname qrcode
+qr_scanner <- function(){
+  ocv_video(function(im){
+    out <- ocv_qrmask(im)
+    value <- attr(out, 'value')
+    if(length(value)){
+      list(out = out, value = value)
+    }
+  }, stop_on_result = TRUE)
+}

man/qrcode.Rd

@@ -246,13 +246,15 @@ BEGIN_RCPP
 END_RCPP
 }
 // livestream
-void livestream(Rcpp::Function filter);
-RcppExport SEXP _opencv_livestream(SEXP filterSEXP) {
+Rcpp::RObject livestream(Rcpp::Function filter, bool stop_on_result);
+RcppExport SEXP _opencv_livestream(SEXP filterSEXP, SEXP stop_on_resultSEXP) {
 BEGIN_RCPP
+    Rcpp::RObject rcpp_result_gen;
     Rcpp::RNGScope rcpp_rngScope_gen;
     Rcpp::traits::input_parameter< Rcpp::Function >::type filter(filterSEXP);
-    livestream(filter);
-    return R_NilValue;
+    Rcpp::traits::input_parameter< bool >::type stop_on_result(stop_on_resultSEXP);
+    rcpp_result_gen = Rcpp::wrap(livestream(filter, stop_on_result));
+    return rcpp_result_gen;
 END_RCPP
 }
 // data_prefix
@@ -507,7 +509,7 @@ static const R_CallMethodDef CallEntries[] = {
     {"_opencv_cvmat_copyto", (DL_FUNC) &_opencv_cvmat_copyto, 3},
     {"_opencv_cvmat_info", (DL_FUNC) &_opencv_cvmat_info, 1},
     {"_opencv_cvmat_display", (DL_FUNC) &_opencv_cvmat_display, 1},
-    {"_opencv_livestream", (DL_FUNC) &_opencv_livestream, 1},
+    {"_opencv_livestream", (DL_FUNC) &_opencv_livestream, 2},
     {"_opencv_data_prefix", (DL_FUNC) &_opencv_data_prefix, 0},
     {"_opencv_set_num_threads", (DL_FUNC) &_opencv_set_num_threads, 1},
     {"_opencv_cvmat_grayscale", (DL_FUNC) &_opencv_cvmat_grayscale, 1},

src/RcppExports.cpp

@@ -175,25 +175,46 @@ void cvmat_display(XPtrMat ptr){
 }
 
 // [[Rcpp::export]]
-void livestream(Rcpp::Function filter){
+Rcpp::RObject livestream(Rcpp::Function filter, bool stop_on_result = false){
   VideoCapture cap(0);
   if(!cap.isOpened())
     throw std::runtime_error("Failed to open Camera");
   Mat image;
   namedWindow("mywindow", 1);
+  Rcpp::RObject out = R_NilValue;
   try {
     for(int i = 0;;i++) {
       cap >> image;
-      XPtrMat out(filter(cvmat_xptr(image)));
-      imshow("mywindow", get_mat(out));
+      Rcpp::RObject val = filter(cvmat_xptr(image));
+      if(stop_on_result){
+        if(val != R_NilValue){
+          out = val;
+          break;
+        }
+        imshow("mywindow", image);
+      } else {
+        if(val.inherits("opencv-image")){
+          imshow("mywindow", get_mat(XPtrMat(val)));
+        } else {
+          REprintf("\rFilter function did not return opencv-image object. Showing input image. (%d)", i);
+          imshow("mywindow", image);
+        }
+      }
       if(waitKey(30) >= 0 || cv::getWindowProperty("mywindow", 0) < 0)
         break;
       Rcpp::checkUserInterrupt();
     }
-  } catch(Rcpp::internal::InterruptedException e) { }
-  cap.release();
-  cv::destroyWindow("mywindow");
-  cv::waitKey(1);
+  } catch(Rcpp::internal::InterruptedException e) {
+    cap.release();
+    cv::destroyWindow("mywindow");
+    cv::waitKey(1);
+  } catch(std::exception e) {
+    cap.release();
+    cv::destroyWindow("mywindow");
+    cv::waitKey(1);
+    throw e;
+  }
+  return out;
 }
 
 // [[Rcpp::export]]

src/base.cpp

@@ -29,7 +29,7 @@ XPtrMat cvmat_qrmask(XPtrMat ptr){
                 1.0,
                 CV_RGB(118, 185, 0), //font color
                 2);
-
+    ptr.attr("value") = Rcpp::CharacterVector::create(data);
   }
   return ptr;
 }