OpenCV image treatments

[luiztauffer]

• [x] grayscale (https://techtutorialsx.com/2018/06/02/python-opencv-converting-an-image-to-gray-scale/) https://github.com/Tauffer-Consulting/opencv_flowui_operators/pull/2
• [x] gradients (https://docs.opencv.org/4.x/d5/d0f/tutorial_py_gradients.html) https://github.com/Tauffer-Consulting/opencv_flowui_operators/pull/2
• [x] blur (https://docs.opencv.org/4.x/d4/d13/tutorial_py_filtering.html) https://github.com/Tauffer-Consulting/opencv_flowui_operators/pull/2
• [x] thresholding (https://docs.opencv.org/4.x/d7/d4d/tutorial_py_thresholding.html) https://github.com/Tauffer-Consulting/opencv_flowui_operators/pull/2
• [x] morphological transformations (https://docs.opencv.org/4.x/d9/d61/tutorial_py_morphological_ops.html) https://github.com/Tauffer-Consulting/opencv_flowui_operators/pull/2
• [x] edge detection (https://docs.opencv.org/4.x/da/d22/tutorial_py_canny.html) https://github.com/Tauffer-Consulting/opencv_flowui_operators/pull/2

De-noising with:

• [ ] bilateral filter (https://docs.opencv.org/4.x/d4/d13/tutorial_py_filtering.html)
• [ ] opening and closing (https://docs.opencv.org/4.x/d9/d61/tutorial_py_morphological_ops.html)

[BrunoSerafim]

https://github.com/Tauffer-Consulting/opencv_flowui_operators/pull/2