基于OPENCV和CVui的智能车图像处理

# cvui A (very) simple UI lib built on top of OpenCV drawing primitives. Other UI libs, such as [imgui](https://github.com/ocornut/imgui), require a graphical backend (e.g. OpenGL) to work, so if you want to use imgui in a OpenCV app, you must make it OpenGL enabled, for instance. It is not the case with cvui, which uses *only* OpenCV drawing primitives to do all the rendering (no OpenGL or Qt required).  ## Features - Lightweight and simple to use user interface; - Header-only with no external dependencies (except OpenCV); - Based on OpenCV drawing primitives only (OpenGL or Qt are not required); - Friendly and C-like API (no classes/objects, etc); - Easily render components without worrying about their position (using rows/columns); - Simple (yet powerful) mouse API; - Modest number of UI components (11 in total); - Available in C++ and Python (pure implementation, no bindings). ## Usage Use of cvui revolves around calling `cvui.init()` to initialize the lib, rendering cvui components to a `np.ndarray` (that you handle yourself) and finally showing that `np.ndarray` on the screen using `cvui.imshow()`, which is cvui's version of `cv2.imshow()`. Alternatively you can use `cv2.imshow()` to show things, but in such case you must call `cvui.update()` yourself before calling `cv.imshow()`. Below is an example: ```python import numpy as np import cv2 import cvui WINDOW_NAME = 'CVUI Test' # Initialize cvui and create/open a OpenCV window. cvui.init(WINDOW_NAME) # Create a frame to render components to. frame = np.zeros((200, 400, 3), np.uint8) while True: # Clear the frame. frame[:] = (49, 52, 49) # Render a message in the frame at position (10, 15) cvui.text(frame, 10, 15, 'Hello world!') # Show frame in a window. cvui.imshow(WINDOW1_NAME, frame) if cv2.waitKey(20) == 27: break ``` The following sections explain in detail each one of the steps required to use cvui. ### 1. Import and initialize cvui Before using cvui, you need to call `cvui.init()` to initialize it. The easiest way is to initialize cvui and tell it to create any OpenCV window that will be used, e.g.: ```python import numpy as np import cv2 import cvui WINDOW_NAME = 'CVUI Test' # Tell cvui to init and create a window cvui.init(WINDOW_NAME) while True: # your app logic here if cv2.waitKey(20) == 27: break ``` **Tip:** if you need to use cvui with multiple windows, or you want more control over the process of creating windows, check the <a href="https://dovyski.github.io/cvui/advanced-multiple-windows">Multiple OpenCV windows</a> page and the <a href="https://github.com/Dovyski/cvui/tree/master/example/src/multiple-windows">multiple-windows</a> and <a href="https://github.com/Dovyski/cvui/tree/master/example/src/multiple-windows-complex">multiple-windows-complex</a> examples.</div> ### 2. Rendering and using cvui components All cvui components are rendered to a `np.ndarray`. Below is an example showing how to render a `'Hello world'` message on a `np.ndarray` named `frame`: ```python import numpy as np import cv2 import cvui WINDOW_NAME = 'CVUI Test' cvui.init(WINDOW_NAME) # Create a frame frame = np.zeros((200, 400, 3), np.uint8) while True: # clear the frame frame[:] = (49, 52, 49) # render a message in the frame at position (10, 15) cvui.text(frame, 10, 15, 'Hello world!') if cv2.waitKey(20) == 27: break ``` Some cvui components, i.e. <a href="https://dovyski.github.io/cvui/components/counter/">counter</a>, <a href="https://dovyski.github.io/cvui/components/trackbar/">trackbar</a> and <a href="https://dovyski.github.io/cvui/components/checkbox/">checkbox</a>.</div>, use an external variable that they need to modify to control their internal state. Since there are no pointers to built-in types in Python, cvui components that need to change an external variable must receive such variable as an array/list with a single element. Below is an example of a checkbox whose state is stored in the variable `checkboxState`: ```python import numpy as np import cv2 import cvui WINDOW_NAME = 'CVUI Test' cvui.init(WINDOW_NAME) frame = np.zeros((200, 400, 3), np.uint8) # use an array/list because this variable will be changed by cvui checkboxState = [False] while True: frame[:] = (49, 52, 49) # Render the checkbox. Notice that checkboxState is used AS IS, # e.g. simply "checkboxState" instead of "checkboxState[0]". # Only internally that cvui will use checkboxState[0]. cvui.checkbox(frame, 10, 15, 'My checkbox', checkboxState) # Check the state of the checkbox. Here you need to remember to # use the first position of the array/list because that's the # one being used by all cvui components that perform changes # to external variables. if checkboxState[0] == True: print('Checkbox is checked') if cv2.waitKey(20) == 27: break ``` **Tip:** see the <a href="https://dovyski.github.io/cvui/">online documentation</a> to learn more about all available cvui components. ### 3. Show (window) content After rendering your components, show the final result using `cvui.imshow()`, which is cvui's improved version of OpenCV's `cv2.imshow()`: ```python import numpy as np import cv2 import cvui WINDOW_NAME = 'CVUI Test' cvui.init(WINDOW_NAME) frame = np.zeros((200, 400, 3), np.uint8) while True: frame[:] = (49, 52, 49) cvui.text(frame, 10, 15, 'Hello world!') # Show window content cvui.imshow(WINDOW1_NAME, frame) if cv2.waitKey(20) == 27: break ``` When you use `cvui.imshow()` instead of `cv2.imshow()`, cvui will not only show the content, but update its internal structures to ensure all UI interactions work. If you want to use `cv2.imshow()`, you must call `cvui.update()` before `cv2.imshow()` and after you are finished invoking cvui components, so cvui can perform its internal processing to handle mouse interactions. E.g. ```python import numpy as np import cv2 import cvui WINDOW_NAME = 'CVUI Test' cvui.init(WINDOW_NAME) frame = np.zeros((200, 400, 3), np.uint8) while True: frame[:] = (49, 52, 49) cvui.text(frame, 10, 15, 'Hello world!') # Update cvui internal stuff cvui.update() # Show window content cv2.imshow(WINDOW1_NAME, frame) if cv2.waitKey(20) == 27: break ```