""" ************************************************************************* // Example program using OpenCV library // python >3.7 - OpenCV 4.5 // @file e8.py // @author Luis M. Jimenez // @date 2022 // // @brief Course: Computer Vision (1782) // Dept. of Systems Engineering and Automation // Automation, Robotics and Computer Vision Lab (ARVC) // http://arvc.umh.es // University Miguel Hernandez // // @note Description: // - This example captures images from a camera, shows them in a window and... // - Enables a handler for mouse events // - Saves window image on leftmouse+Shift click // - Saves window image on Space bar or F5 keystroke // - Calibrate camera // - Save calibration data to JSON // ************************************************************************* """ # Import libraries import cv2 as cv import numpy as np import argparse import os import json # ----------------------------------------- # Functions # ----------------------------------------- """ //---------------------------------------------------------------------- // Mouse events handler for image window //---------------------------------------------------------------------- // event: event type sent to the handler -> cv.EVENT_MOUSEMOVE, // cv.EVENT_LBUTTONDOWN, cv.EVENT_LBUTTONUP, cv.EVENT_LBUTTONDBLCLK, // cv.EVENT_RBUTTONDOWN, cv.EVENT_RBUTTONUP, cv.EEVENT_RBUTTONDBLCLK, // cv.EVENT_MBUTTONDOWN, cv.EVENT_MBUTTONUP, cv.EEVENT_MBUTTONDBLCLK, // cv.EVENT_MOUSEWHEEL, cv.EVENT_MOUSEHWHEEL // x: X-coordinate position of the mouse in window // y: Y-coordinate position of the mouse in window // flags: aditional flags sent to the handler -> // cv.EVENT_FLAG_SHIFTKEY, cv.EVENT_FLAG_CTRLKEY, cv.EVENT_FLAG_ALTKEY, // cv.EVENT_FLAG_LBUTTON, cv.EVENT_FLAG_RBUTTON, cv.EVENT_FLAG_MBUTTON, // param: set in cv.SetMouseCallback //---------------------------------------------------------------------- """ def onMouse(event, x, y, flags, param): global ID_FILE, capture # global variables used in the mouse handler # print(f"{event=}, {x=}, {y=}, {flags=}, {param=}") # on click left mouse button and SHIFT key, saves image if event==cv.EVENT_LBUTTONDOWN and (flags & cv.EVENT_FLAG_SHIFTKEY): filename = f"Image{ID_FILE}.jpg" print(f"Saving image window in file: {filename}") cv.imwrite(filename, capture) # save window image ID_FILE += 1 # ----------------------------------------- # Global variables # ----------------------------------------- WINDOW_CAMERA1 = '(W1) Camera 1' # window id CAMERA_ID = 0 # default camera KEY_F5 = 7602176 # F5 unicode key code ID_FILE = 1 # filename id # check command line parameters (camera id) parser = argparse.ArgumentParser(description='OpenCV example: captures images from a camera') parser.add_argument('-c', dest='cameraID', type=int, default=CAMERA_ID, metavar='id', help='camera id') CAMERA_ID = parser.parse_args().cameraID # ----------------------------------------- # Put here the code to Initialize objets # ----------------------------------------- # Open camera object camera = cv.VideoCapture(CAMERA_ID) if not camera.isOpened(): print("you need to connect a camera, sorry.") exit() # Getting camera resolution cameraWidth = int(camera.get(cv.CAP_PROP_FRAME_WIDTH)) cameraHeight = int(camera.get(cv.CAP_PROP_FRAME_HEIGHT)) # Creating visualization windows cv.namedWindow(WINDOW_CAMERA1, cv.WINDOW_AUTOSIZE) # Setting Mouse Handler cv.setMouseCallback(WINDOW_CAMERA1, onMouse) print(f"Capturing images from camera {CAMERA_ID} ({cameraWidth},{cameraHeight})") print("...Hit F5 or Space bar to capture and save the image") print("...Hit q/Q/Esc to exit.") # ----------------------------------------- # Main Loop # while there are images ... # ----------------------------------------- while True: # Capture frame-by-frame ret, capture = camera.read() # if frame is read correctly ret is True if not ret: print("Can't receive frame (stream end?). Exiting ...") break # ----------------------------------------- # Put your image processing code here # ----------------------------------------- # ----------------------------------------- # Put your visualization code here # ----------------------------------------- cv.imshow(WINDOW_CAMERA1, capture) # Display the resulting frame # check keystroke to exit (image window must be on focus) key = cv.pollKey() if key == ord('q') or key == ord('Q') or key == 27: break elif key == KEY_F5 or key == ord(' '): filename = f"Image{ID_FILE}.jpg" print(f"Saving image window in file: {filename}") cv.imwrite(filename, capture) # save window image ID_FILE += 1 # End while (main loop) # ----------------------------------------- # Calibrate camera with stored image files (calibration pattern) # Calibration pattern inner corners (width Y-axis, height X-axis) patternSize = (8, 6) squareSize = 27.0 # square pattern side in mm # 3D object points coordinates (x,y,z) objp3D = np.zeros((patternSize[1], patternSize[0], 3), np.float32) for x in range(patternSize[1]): for y in range(patternSize[0]): objp3D[x,y] = (x*squareSize, y*squareSize, 0) objp3D = objp3D.reshape(-1, 3) # transform in a row vector of (x,y,z) tuples objpoints = [] # 3D point in real world space imgpoints = [] # 2D points in image plane num_patterns = 0 # number of detected patterns. We need at lest 3 # reading directory files valid_extension = ('jpg', 'jpeg', 'png', 'tiff', 'tif', 'bmp', 'pgm') directoryList = sorted(os.listdir(".")) for file in directoryList: # Filter non image files if not file.endswith(valid_extension): continue print(f"Processing image file: {file}") image = cv.imread(file) gray_image = cv.cvtColor(image, cv.COLOR_BGR2GRAY) # transforms to gray level # Calibration pattern inner corners (cols Y-axis, rows X-axis) patternWasFound, corners = cv.findChessboardCorners(gray_image, patternSize) if patternWasFound: num_patterns += 1 # Iterative algorithm termination criteria termCriteria = (cv.TERM_CRITERIA_EPS + cv.TERM_CRITERIA_MAX_ITER, 30, 0.001) corners = cv.cornerSubPix(gray_image, corners, winSize=(11,11), zeroZone=(-1,-1), criteria=termCriteria) # add points to image/3Dobjet lists objpoints.append(objp3D) imgpoints.append(corners) # Draw and display the corners cv.drawChessboardCorners(image, patternSize, corners, patternWasFound) cv.imshow(WINDOW_CAMERA1, image) # Display the resulting frame key = cv.waitKey(1000) # update image and wait 1 second # end for file in os.listdir("."): if num_patterns >= 3: # imageSize: (width, height) imageSize=gray_image.shape[::-1] # store size as (cols,rows), shape returns (rows,cols)) termCriteria = (cv.TERM_CRITERIA_EPS + cv.TERM_CRITERIA_MAX_ITER, 30, 0.001) rms, cameraMatrix, distCoeffs, rvecs, tvecs = cv.calibrateCamera(objpoints, imgpoints, imageSize=imageSize, cameraMatrix=None, distCoeffs=None, flags=0, criteria=termCriteria) print(f"RMS reprojection error: {rms}") # store calibration data in a JSON file with open('camera_calib.json', 'w') as file: json.dump({'camera_matrix': cameraMatrix.tolist(), 'distortion_coefficients': distCoeffs.tolist(), 'nx': imageSize[0], # width (x-axis) 'ny': imageSize[1], # height (y-axis) 'rms': rms }, file, indent=4) # Reading calibration data from file try: with open('camera_calib.json') as file: data = json.load(file) if 'camera_matrix' in data: camera_matrix = np.array(data['camera_matrix']) if 'distortion_coefficients' in data: distortion_coefficients = np.array(data['distortion_coefficients']) print('Camera matrix:', camera_matrix) print('distortion_coefficients:', distortion_coefficients) except: print("File not valid") # ----------------------------------------- # free windows and camera resources # ----------------------------------------- cv.destroyAllWindows() if camera.isOpened(): camera.release()