diff --git a/modules/dnn/include/opencv2/dnn/blob.hpp b/modules/dnn/include/opencv2/dnn/blob.hpp
index 72f644d8c..22c94d93f 100644
--- a/modules/dnn/include/opencv2/dnn/blob.hpp
+++ b/modules/dnn/include/opencv2/dnn/blob.hpp
@@ -209,6 +209,13 @@ namespace dnn
          */
         Mat getPlane(int n, int cn);
 
+        /** @brief Returns slice of first dimension.
+         *  @details The behaviour is similar to getPlane(), but returns all
+         * channels * rows * cols values, corresponding to the n-th value
+         * of the first dimension.
+         */
+        Mat getPlanes(int n);
+
         /* Shape getters of 4-dimensional blobs. */
         int cols() const;       //!< Returns size of the fourth axis blob.
         int rows() const;       //!< Returns size of the thrid  axis blob.
diff --git a/modules/dnn/include/opencv2/dnn/blob.inl.hpp b/modules/dnn/include/opencv2/dnn/blob.inl.hpp
index 6e18716f5..bd9aded85 100644
--- a/modules/dnn/include/opencv2/dnn/blob.inl.hpp
+++ b/modules/dnn/include/opencv2/dnn/blob.inl.hpp
@@ -391,6 +391,12 @@ inline Mat Blob::getPlane(int n, int cn)
     return Mat(dims() - 2, sizes() + 2, type(), ptr(n, cn));
 }
 
+inline Mat Blob::getPlanes(int n)
+{
+    CV_Assert(dims() > 3);
+    return Mat(dims() - 1, sizes() + 1, type(), ptr(n));
+}
+
 inline int Blob::cols() const
 {
     return xsize(3);
diff --git a/modules/dnn/include/opencv2/dnn/dict.hpp b/modules/dnn/include/opencv2/dnn/dict.hpp
index 9bc83f5f1..d04091a14 100644
--- a/modules/dnn/include/opencv2/dnn/dict.hpp
+++ b/modules/dnn/include/opencv2/dnn/dict.hpp
@@ -111,7 +111,7 @@ class CV_EXPORTS Dict
 public:
 
     //! Checks a presence of the @p key in the dictionary.
-    bool has(const String &key);
+    bool has(const String &key) const;
 
     //! If the @p key in the dictionary then returns pointer to its value, else returns NULL.
     DictValue *ptr(const String &key);
diff --git a/modules/dnn/include/opencv2/dnn/dnn.inl.hpp b/modules/dnn/include/opencv2/dnn/dnn.inl.hpp
index 336f09d8e..a27204402 100644
--- a/modules/dnn/include/opencv2/dnn/dnn.inl.hpp
+++ b/modules/dnn/include/opencv2/dnn/dnn.inl.hpp
@@ -287,7 +287,7 @@ inline std::ostream &operator<<(std::ostream &stream, const DictValue &dictv)
 
 /////////////////////////////////////////////////////////////////
 
-inline bool Dict::has(const String &key)
+inline bool Dict::has(const String &key) const
 {
     return dict.count(key) != 0;
 }