diff --git a/apps/createsamples/utility.cpp b/apps/createsamples/utility.cpp
index b57d3fcb81..87ba4eac5a 100644
--- a/apps/createsamples/utility.cpp
+++ b/apps/createsamples/utility.cpp
@@ -766,7 +766,6 @@ CvBackgroundData* icvCreateBackgroundData( const char* filename, Size winsize )
         }
         if( count > 0 )
         {
-            //rewind( input );
             fseek( input, 0, SEEK_SET );
             datasize += sizeof( *data ) + sizeof( char* ) * count;
             data = (CvBackgroundData*) fastMalloc( datasize );
@@ -872,8 +871,6 @@ void icvGetNextFromBackgroundData( CvBackgroundData* data,
 
     reader->src = img;
 
-    //reader->offset.x = round % data->winsize.width;
-    //reader->offset.y = round / data->winsize.width;
     reader->offset = offset;
     reader->point = reader->offset;
     reader->scale = MAX(
diff --git a/modules/highgui/include/opencv2/highgui.hpp b/modules/highgui/include/opencv2/highgui.hpp
index 35b64bceae..dec9af5b46 100644
--- a/modules/highgui/include/opencv2/highgui.hpp
+++ b/modules/highgui/include/opencv2/highgui.hpp
@@ -531,16 +531,20 @@ control panel.
 Clicking the label of each trackbar enables editing the trackbar values manually.
 
 @param trackbarname Name of the created trackbar.
-@param winname Name of the window that will be used as a parent of the created trackbar.
-@param value Optional pointer to an integer variable whose value reflects the position of the
-slider. Upon creation, the slider position is defined by this variable.
-@param count Maximal position of the slider. The minimal position is always 0.
-@param onChange Pointer to the function to be called every time the slider changes position. This
-function should be prototyped as void Foo(int,void\*); , where the first parameter is the trackbar
-position and the second parameter is the user data (see the next parameter). If the callback is
-the NULL pointer, no callbacks are called, but only value is updated.
-@param userdata User data that is passed as is to the callback. It can be used to handle trackbar
-events without using global variables.
+@param winname Name of the window that will contain the trackbar.
+@param value Pointer to the integer value that will be changed by the trackbar.
+Pass `nullptr` if the value pointer is not used. In this case, manually handle
+the trackbar position in the callback function.
+@param count Maximum position of the trackbar.
+@param onChange Pointer to the function to be called every time the slider changes position.
+This function should have the prototype void Foo(int, void\*);, where the first parameter is
+the trackbar position, and the second parameter is the user data (see the next parameter).
+If the callback is a nullptr, no callbacks are called, but the trackbar's value will still be
+updated automatically.
+@param userdata Optional user data that is passed to the callback.
+@note If the `value` pointer is `nullptr`, the trackbar position must be manually managed.
+Call the callback function manually with the desired initial value to avoid runtime warnings.
+@see #tutorial_trackbar
  */
 CV_EXPORTS int createTrackbar(const String& trackbarname, const String& winname,
                               int* value, int count,
diff --git a/samples/cpp/tutorial_code/HighGUI/AddingImagesTrackbar.cpp b/samples/cpp/tutorial_code/HighGUI/AddingImagesTrackbar.cpp
index 82bbb3743a..3650b15dea 100644
--- a/samples/cpp/tutorial_code/HighGUI/AddingImagesTrackbar.cpp
+++ b/samples/cpp/tutorial_code/HighGUI/AddingImagesTrackbar.cpp
@@ -27,12 +27,12 @@ Mat dst;
  * @function on_trackbar
  * @brief Callback for trackbar
  */
-static void on_trackbar( int, void* )
-{
-   alpha = (double) alpha_slider/alpha_slider_max ;
-   beta = ( 1.0 - alpha );
-   addWeighted( src1, alpha, src2, beta, 0.0, dst);
-   imshow( "Linear Blend", dst );
+static void on_trackbar(int pos, void* userdata) {
+    (void) userdata;
+    alpha = (double)pos / alpha_slider_max;
+    beta = (1.0 - alpha);
+    addWeighted(src1, alpha, src2, beta, 0.0, dst);
+    imshow("Linear Blend", dst);
 }
 //![on_trackbar]
 
@@ -40,34 +40,35 @@ static void on_trackbar( int, void* )
  * @function main
  * @brief Main function
  */
-int main( void )
+int main(void)
 {
-   //![load]
-   /// Read images ( both have to be of the same size and type )
-   src1 = imread( samples::findFile("LinuxLogo.jpg") );
-   src2 = imread( samples::findFile("WindowsLogo.jpg") );
-   //![load]
+    //![load]
+    /// Read images (both must be of the same size and type)
+    src1 = imread(samples::findFile("LinuxLogo.jpg"));
+    src2 = imread(samples::findFile("WindowsLogo.jpg"));
+    //![load]
 
-   if( src1.empty() ) { cout << "Error loading src1 \n"; return -1; }
-   if( src2.empty() ) { cout << "Error loading src2 \n"; return -1; }
+    if (src1.empty()) { cout << "Error loading src1 \n"; return -1; }
+    if (src2.empty()) { cout << "Error loading src2 \n"; return -1; }
 
-   /// Initialize values
-   alpha_slider = 0;
+    // Initialize trackbar value
+    alpha_slider = 0;
 
-   //![window]
-   namedWindow("Linear Blend", WINDOW_AUTOSIZE); // Create Window
-   //![window]
+    //![window]
+    namedWindow("Linear Blend", WINDOW_AUTOSIZE); //Create Window
+    //![window]
 
-   //![create_trackbar]
-   char TrackbarName[50];
-   snprintf( TrackbarName, sizeof(TrackbarName), "Alpha x %d", alpha_slider_max );
-   createTrackbar( TrackbarName, "Linear Blend", &alpha_slider, alpha_slider_max, on_trackbar );
-   //![create_trackbar]
+    //![create_trackbar]
+    char TrackbarName[50];
+    snprintf(TrackbarName, sizeof(TrackbarName), "Alpha x %d", alpha_slider_max);
+    // Example userdata: Pass a pointer to an integer as userdata
+    createTrackbar(TrackbarName, "Linear Blend", &alpha_slider, alpha_slider_max, on_trackbar);
+    //![create_trackbar]
 
-   /// Show some stuff
-   on_trackbar( alpha_slider, 0 );
+    /// Show initial result
+    on_trackbar(alpha_slider, nullptr);
 
-   /// Wait until user press some key
-   waitKey(0);
-   return 0;
+    /// Wait for user input
+    waitKey(0);
+    return 0;
 }