Merge pull request #25608 from sturkmen72:animated_webp_support

Animated WebP Support #25608

related issues #24855 #22569 

### Pull Request Readiness Checklist

See details at https://github.com/opencv/opencv/wiki/How_to_contribute#making-a-good-pull-request

- [x] I agree to contribute to the project under Apache 2 License.
- [x] To the best of my knowledge, the proposed patch is not based on a code under GPL or another license that is incompatible with OpenCV
- [x] The PR is proposed to the proper branch
- [x] There is a reference to the original bug report and related work
- [ ] There is accuracy test, performance test and test data in opencv_extra repository, if applicable
      Patch to opencv_extra has the same branch name.
- [ ] The feature is well documented and sample code can be built with the project CMake

doc/tutorials/app/animations.markdown

@@ -0,0 +1,91 @@
+Handling Animated Image Files {#tutorial_animations}
+===========================
+
+@tableofcontents
+
+|    |    |
+| -: | :- |
+| Original author | Suleyman Turkmen (with help of ChatGPT) |
+| Compatibility | OpenCV >= 4.11 |
+
+Goal
+----
+In this tutorial, you will learn how to:
+
+- Use `cv::imreadanimation` to load frames from animated image files.
+- Understand the structure and parameters of the `cv::Animation` structure.
+- Display individual frames from an animation.
+- Use `cv::imwriteanimation` to write `cv::Animation` to a file.
+
+Source Code
+-----------
+
+@add_toggle_cpp
+-   **Downloadable code**: Click
+    [here](https://github.com/opencv/opencv/tree/4.x/samples/cpp/tutorial_code/imgcodecs/animations.cpp)
+
+-   **Code at a glance:**
+    @include samples/cpp/tutorial_code/imgcodecs/animations.cpp
+@end_toggle
+
+@add_toggle_python
+-   **Downloadable code**: Click
+    [here](https://github.com/opencv/opencv/tree/4.x/samples/python/tutorial_code/imgcodecs/animations.py)
+
+-   **Code at a glance:**
+    @include samples/python/tutorial_code/imgcodecs/animations.py
+@end_toggle
+
+Explanation
+-----------
+
+## Initializing the Animation Structure
+
+   Initialize a `cv::Animation` structure to hold the frames from the animated image file.
+
+@add_toggle_cpp
+@snippet cpp/tutorial_code/imgcodecs/animations.cpp init_animation
+@end_toggle
+
+@add_toggle_python
+@snippet python/tutorial_code/imgcodecs/animations.py init_animation
+@end_toggle
+
+## Loading Frames
+
+   Use `cv::imreadanimation` to load frames from the specified file. Here, we load all frames from an animated WebP image.
+
+@add_toggle_cpp
+@snippet cpp/tutorial_code/imgcodecs/animations.cpp read_animation
+@end_toggle
+
+@add_toggle_python
+@snippet python/tutorial_code/imgcodecs/animations.py read_animation
+@end_toggle
+
+## Displaying Frames
+
+   Each frame in the `animation.frames` vector can be displayed as a standalone image. This loop iterates through each frame, displaying it in a window with a short delay to simulate the animation.
+
+@add_toggle_cpp
+@snippet cpp/tutorial_code/imgcodecs/animations.cpp show_animation
+@end_toggle
+
+@add_toggle_python
+@snippet python/tutorial_code/imgcodecs/animations.py show_animation
+@end_toggle
+
+## Saving Animation
+
+@add_toggle_cpp
+@snippet cpp/tutorial_code/imgcodecs/animations.cpp write_animation
+@end_toggle
+
+@add_toggle_python
+@snippet python/tutorial_code/imgcodecs/animations.py write_animation
+@end_toggle
+
+## Summary
+
+The `cv::imreadanimation` and `cv::imwriteanimation` functions make it easy to work with animated image files by loading frames into a `cv::Animation` structure, allowing frame-by-frame processing.
+With these functions, you can load, process, and save frames from animated image files like GIF, AVIF, APNG, and WebP.

doc/tutorials/app/table_of_content_app.markdown

@@ -10,3 +10,4 @@ Application utils (highgui, imgcodecs, videoio modules) {#tutorial_table_of_cont
 -   @subpage tutorial_orbbec_uvc
 -   @subpage tutorial_intelperc
 -   @subpage tutorial_wayland_ubuntu
+-   @subpage tutorial_animations