Added fixes mentioned in bugreport 3306

- Added author provided fixes
- Added code example
- Added documentation fixes

modules/highgui/doc/reading_and_writing_images_and_video.rst

@@ -253,7 +253,7 @@ VideoCapture constructors.
 .. ocv:cfunction:: CvCapture* cvCaptureFromFile( const char* filename )
 .. ocv:pyoldfunction:: cv.CaptureFromFile(filename) -> CvCapture
 
-    :param filename: name of the opened video file
+    :param filename: name of the opened video file (eg. video.avi) or image sequence (eg. img_%02d.jpg, which will read samples like img_00.jpg, img_01.jpg, img_02.jpg, ...)
 
     :param device: id of the opened video capturing device (i.e. a camera index). If there is a single camera connected, just pass 0.
 
@@ -270,7 +270,7 @@ Open video file or a capturing device for video capturing
 .. ocv:pyfunction:: cv2.VideoCapture.open(filename) -> retval
 .. ocv:pyfunction:: cv2.VideoCapture.open(device) -> retval
 
-    :param filename: name of the opened video file
+    :param filename: name of the opened video file (eg. video.avi) or image sequence (eg. img_%02d.jpg, which will read samples like img_00.jpg, img_01.jpg, img_02.jpg, ...)
 
     :param device: id of the opened video capturing device (i.e. a camera index).
 

samples/cpp/image_sequence.cpp

+#include <opencv2/core/core.hpp>
+#include <opencv2/highgui/highgui.hpp>
+
+#include <iostream>
+
+using namespace cv;
+using namespace std;
+
+static void help(char** argv)
+{
+    cout << "\nThis sample shows you how to read a sequence of images using the VideoCapture interface.\n"
+         << "Usage: " << argv[0] << " <image_mask> (example mask: example_%02d.jpg)\n"
+         << "Image mask defines the name variation for the input images that have to be read as a sequence. \n"
+         << "Using the mask example_%02d.jpg will read in images labeled as 'example_00.jpg', 'example_01.jpg', etc."
+         << endl;
+}
+
+int main(int argc, char** argv)
+{
+    if(argc != 2)
+    {
+        help(argv);
+        return 1;
+    }
+
+    string first_file = argv[1];
+    VideoCapture sequence(first_file);
+
+    if (!sequence.isOpened())
+    {
+        cerr << "Failed to open the image sequence!\n" << endl;
+        return 1;
+    }
+
+    Mat image;
+    namedWindow("Image sequence | press ESC to close", 1);
+
+    for(;;)
+    {
+        // Read in image from sequence
+        sequence >> image;
+
+        // If no image was retrieved -> end of sequence
+        if(image.empty())
+        {
+            cout << "End of Sequence" << endl;
+            break;
+        }
+
+        imshow("Image sequence | press ESC to close", image);
+
+        if(waitKey(500) == 27)
+            break;
+    }
+
+    return 0;
+}