diff --git a/modules/core/include/opencv2/core.hpp b/modules/core/include/opencv2/core.hpp
index 6cfdec1b59..f75c76ec05 100644
--- a/modules/core/include/opencv2/core.hpp
+++ b/modules/core/include/opencv2/core.hpp
@@ -3114,6 +3114,10 @@ class CV_EXPORTS Algorithm;
 template<typename _Tp, typename _EnumTp = void> struct ParamType {};
 
 
+/** @example samples/cpp/snippets/detect_blob.cpp
+An example using the BLOB to detect and filter region.
+*/
+
 /** @brief This is a base class for all more or less complex algorithms in OpenCV
 
 especially for classes of algorithms, for which there can be multiple implementations. The examples
@@ -3125,9 +3129,6 @@ etc.).
 Here is example of SimpleBlobDetector use in your application via Algorithm interface:
 @snippet snippets/core_various.cpp Algorithm
 
-@example samples/cpp/snippets/detect_blob.cpp
-An example using the BLOB to detect and filter region.
-
 */
 class CV_EXPORTS_W Algorithm
 {
diff --git a/modules/objdetect/include/opencv2/objdetect.hpp b/modules/objdetect/include/opencv2/objdetect.hpp
index 9c409ece27..2fbe7e7127 100644
--- a/modules/objdetect/include/opencv2/objdetect.hpp
+++ b/modules/objdetect/include/opencv2/objdetect.hpp
@@ -87,6 +87,7 @@ namespace cv
 //! @addtogroup objdetect_qrcode
 //! @{
 
+/** @brief QR code encoder. */
 class CV_EXPORTS_W QRCodeEncoder {
 protected:
     QRCodeEncoder();  // use ::create()
@@ -151,6 +152,8 @@ public:
     CV_WRAP virtual void encodeStructuredAppend(const String& encoded_info, OutputArrayOfArrays qrcodes) = 0;
 
 };
+
+/** @brief QR code detector. */
 class CV_EXPORTS_W_SIMPLE QRCodeDetector : public GraphicalCodeDetector
 {
 public:
@@ -192,6 +195,7 @@ public:
                                               OutputArray straight_qrcode = noArray());
 };
 
+/** @brief QR code detector based on Aruco markers detection code. */
 class CV_EXPORTS_W_SIMPLE QRCodeDetectorAruco : public GraphicalCodeDetector {
 public:
     CV_WRAP QRCodeDetectorAruco();