Crop_Object.py

# Capture the mouse click events in Python and OpenCV
'''
-> draw shape on any image 
-> reset shape on selection
-> crop the selection

Run this code on Python Terminal , 
1.Just change the directory to open this Crop_Object.py file 
2.The frames should be in the same directory as Crop_Object.py file 
Take the frames that you wanna crop one by one and save it in the same directory!
Don't forget to change the name of cropped image , as when you will save the next cropped frame ,
it will overwrite, so to avoid that, just rename!
run the code : python Crop_Object.py --image jimgf148.jpg
@author: Alan Darko , IIIT Bh
'''


# import the necessary packages
import argparse
import cv2

# initialize the list of reference points and boolean indicating
# whether cropping is being performed or not
ref_point = []
cropping = False

def shape_selection(event, x, y, flags, param):
	# grab references to the global variables
	global ref_point, cropping

	# if the left mouse button was clicked, record the starting
	# (x, y) coordinates and indicate that cropping is being
	# performed
	if event == cv2.EVENT_LBUTTONDOWN:
		ref_point = [(x, y)]
		cropping = True

	# check to see if the left mouse button was released
	elif event == cv2.EVENT_LBUTTONUP:
		# record the ending (x, y) coordinates and indicate that
		# the cropping operation is finished
		ref_point.append((x, y))
		cropping = False

		# draw a rectangle around the region of interest
		cv2.rectangle(image, ref_point[0], ref_point[1], (0, 255, 0), 2)
		cv2.imshow("image", image)

# construct the argument parser and parse the arguments
ap = argparse.ArgumentParser()
ap.add_argument("-i", "--image", required=True, help="Path to the image")
args = vars(ap.parse_args())

# load the image, clone it, and setup the mouse callback function
image = cv2.imread(args["image"])
clone = image.copy()
cv2.namedWindow("image")
cv2.setMouseCallback("image", shape_selection)

# keep looping until the 'q' key is pressed
while True:
	# display the image and wait for a keypress
	cv2.imshow("image", image)
	key = cv2.waitKey(1) & 0xFF

	# if the 'r' key is pressed, reset the cropping region
	if key == ord("r"):
		image = clone.copy()

	# if the 'c' key is pressed, break from the loop
	elif key == ord("c"):
		break

# if there are two reference points, then crop the region of interest
# from teh image and display it
if len(ref_point) == 2:
	crop_img = clone[ref_point[0][1]:ref_point[1][1], ref_point[0][0]:ref_point[1][0]]
	cv2.imshow("crop_img", crop_img)
    
	cv2.waitKey(0)

# close all open windows
cv2.destroyAllWindows()
cv2.imwrite("crop.jpg", crop_img)