24 lines
795 B
Python
24 lines
795 B
Python
import cv2
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import numpy as np
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def detect_large_coherent_structures(image: np.array):
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"""Detects large coherent structures on an image.
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References:
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https://stackoverflow.com/questions/60259169/how-to-group-nearby-contours-in-opencv-python-zebra-crossing-detection
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"""
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gray = cv2.cvtColor(image, cv2.COLOR_BGR2GRAY)
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thresh = cv2.threshold(gray, 253, 255, cv2.THRESH_BINARY)[1]
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dilate_kernel = cv2.getStructuringElement(cv2.MORPH_OPEN, (5, 5))
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dilate = cv2.dilate(~thresh, dilate_kernel, iterations=4)
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close_kernel = cv2.getStructuringElement(cv2.MORPH_RECT, (20, 20))
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close = cv2.morphologyEx(dilate, cv2.MORPH_CLOSE, close_kernel, iterations=1)
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cnts, _ = cv2.findContours(close, cv2.RETR_EXTERNAL, cv2.CHAIN_APPROX_SIMPLE)
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return cnts
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