Merge pull request #18064 from akineeic:gsoc_2020_dnn

[GSoC] Develop OpenCV.js DNN modules for promising web use cases together with their tutorials

* [Opencv.js doc] Init commit to add image classification example in opencv.js tutorial

* [Opencv.js doc] Make the code snippet interactive and put the functions into code snippet.

* Fix the utils.loadOpenCv for promise module

* [Opencv.js doc] Code modify and fixed layout issue.

* [Opencv.js doc] Add a JSON file to store parameters for models and show in the web page.

* [Opencv.js doc] Change let to const.

* [Opencv.js doc] Init commit to add image classification example with camera in opencv.js tutorial

* [Opencv.js doc] Init commit to add semantic segmentation example in opencv.js tutorial

* [Opencv.js doc] Add object detection example, supprot YOLOv2

* [Opencv.js doc] Support SSD model for object detection example

* [Opencv.js doc] Add fast neural style transfer example with opencv.js

* [Opencv.js doc] Add pose estimation example in opencv.js tutorial

* Delete whitespace for code check

* [Opencv.js doc] Add object detection example with camera

* [Opencv.js doc] Add json files containing model information to each example

* [Opencv.js doc] Add a js file for common function in dnn example

* [Opencv.js doc] Create single function getBlobFromImage

* [Opencv.js doc] Add url of model into webpage

* [OpenCV.js doc] Update UI for running

* [Opencv.js doc] Load dnn model by input button

* [Opencv.js doc] Fix some UI issues

* [Opencv.js doc] Change code format

Co-authored-by: Ningxin Hu <ningxin.hu@intel.com>

doc/js_tutorials/js_dnn/js_object_detection/js_object_detection.markdown

@@ -0,0 +1,13 @@
+Object Detection Example {#tutorial_js_object_detection}
+=======================================
+
+Goal
+----
+
+- In this tutorial you will learn how to use OpenCV.js dnn module for object detection.
+
+\htmlonly
+<iframe src="../../js_object_detection.html" width="100%"
+        onload="this.style.height=this.contentDocument.body.scrollHeight +'px';">
+</iframe>
+\endhtmlonly

doc/js_tutorials/js_dnn/js_object_detection/js_object_detection_with_camera.markdown

@@ -0,0 +1,13 @@
+Object Detection Example with Camera{#tutorial_js_object_detection_with_camera}
+=======================================
+
+Goal
+----
+
+- In this tutorial you will learn how to use OpenCV.js dnn module for object detection with camera.
+
+\htmlonly
+<iframe src="../../js_object_detection_with_camera.html" width="100%"
+        onload="this.style.height=this.contentDocument.body.scrollHeight +'px';">
+</iframe>
+\endhtmlonly