88 lines
3.0 KiB
Python
88 lines
3.0 KiB
Python
import cv2
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import numpy as np
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'''
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Acquires frames from camera, then adds a red cross as overlay.
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With mouse double clicks, cross can be moved
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'''
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class ImagePointer:
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center_coord : np.ndarray
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center_size : int
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center_thickness : int
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canvas_name : str
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def __init__(self):
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# Cross coordinates
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self.center_coord = np.array((0,0))
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self.center_size = 10
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self.center_thickness = 3
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self.canvas_name = 'Image Pointer'
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self.rotate = False
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# OpenCV callbacks
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def on_mouse_event(self, event, x, y, flags, param):
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# if event == cv2.EVENT_LBUTTONDBLCLK:
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if event == cv2.EVENT_LBUTTONUP:
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# Update cross position
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self.center_coord = np.array((x, y))
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def on_center_size_change(self, value):
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if value > 0:
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self.center_size = value
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def on_center_thickness_change(self, value):
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if value > 0:
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self.center_thickness = value
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def on_rotate_changed(self, value):
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self.rotate = value == 1
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def run(self):
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# Camera feed
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cam = cv2.VideoCapture(0)
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if not cam.isOpened():
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raise Exception('Cannot open camera')
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ret, frame_cam = cam.read()
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if not ret:
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cam.release()
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raise Exception('Cannot open camera stream')
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# Put cross in image center as default
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self.center_coord = np.array((int(cam.get(cv2.CAP_PROP_FRAME_WIDTH)), int(cam.get(cv2.CAP_PROP_FRAME_HEIGHT))))
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self.center_coord //= 2
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cv2.namedWindow(self.canvas_name, cv2.WND_PROP_FULLSCREEN)
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cv2.setMouseCallback(self.canvas_name, self.on_mouse_event)
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cv2.createTrackbar('center size', self.canvas_name, self.center_size, 100, self.on_center_size_change)
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cv2.createTrackbar('center thickness', self.canvas_name, self.center_thickness, 16, self.on_center_thickness_change)
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cv2.createTrackbar('rotate', self.canvas_name, 0, 1, self.on_rotate_changed)
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while True:
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# Capture the next frame from camera
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ret, frame_cam = cam.read()
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if not ret:
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print('Cannot receive frame from camera')
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break
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# Acquire frame
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frame = frame_cam.astype(np.uint8)
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# Rotate if needed
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if self.rotate:
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frame = cv2.rotate(frame, cv2.ROTATE_180)
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## Add cross
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frame = cv2.line(frame, self.center_coord - (0, self.center_size), self.center_coord + (0, self.center_size), (0, 0, 255,), self.center_thickness)
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frame = cv2.line(frame, self.center_coord - (self.center_size, 0), self.center_coord + (self.center_size, 0), (0, 0, 255,), self.center_thickness)
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cv2.imshow(self.canvas_name, frame)
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# detect ESC key or if window is closeed
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if cv2.waitKey(1) == 27 or cv2.getWindowProperty(self.canvas_name,cv2.WND_PROP_VISIBLE) < 1:
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break
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cam.release()
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cv2.destroyAllWindows()
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