License Plate Finder C++ (OpenCV)
Steps
- Find a clear image of a license plate
- Grayscale the image and perform both a bilateral filter and median blur
Both of these methods are effective for removing noise from our image while preserving edges
- Peform canny edge detection on our filtered image to find all the edges.
- Use findContours to extract all the contours from our canny edged image.
- Use approxPolyDB to approximate the polygonal curve of each contour, and only return the output vectors that have an exact size of four.
- Now that we have all our contours with exactly four sides, we can find the one that contains the most contours inside it's bounds. In an application for reading license plates, this data would be processed using OCR.
- Now, we can go ahead and draw that contour to our original image to outline the license plate.
