OpenCV Cropping Utility

crop.py

'''
	Opencv Image Cropper
	Commands:
		s : Overwrite & Save image
		left-arrow : previous
		right-arrow : next
'''

import cv2
import glob
import numpy as np
import sys, os
import argparse


class Cropper:
	def __init__(self, args):
		tmp_resolution = args.get("resolution").split("x")
		self.width, self.height = map(int, tmp_resolution)
		im_path = os.path.join(args.get("base_dir"), args.get("path"))
		self.im_path = sorted(glob.glob(im_path + "/*"), key=lambda x: int(x.split("/")[-1].split(".")[0]))
		print "Path list ", self.im_path

		self.refPt = []
		self.cropping = False

		self.selection = None
		self.drag_start = None
		self.show_backproj = False
		self.track_window = None

		cv2.namedWindow("Image")
		cv2.namedWindow("new")
		cv2.setMouseCallback("Image", self.click_and_crop)

	def click_and_crop(self, event, x, y, flags, param):
		'''
			https://www.pyimagesearch.com/2015/03/09/capturing-mouse-click-events-with-python-and-opencv/
		'''
		if event == cv2.EVENT_LBUTTONDOWN:
			self.refPt = [(x, y)]
			self.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
			self.refPt.append((x, y))
			self.cropping = False

			self.new_image = self.image[self.refPt[0][1]:self.refPt[1][1], self.refPt[0][0]:self.refPt[1][0]]
			cv2.imshow("Image", self.image)
			cv2.imshow("new", self.new_image)
			cv2.rectangle(self.image, self.refPt[0], self.refPt[1], (255, 255, 255), 2)

	def run(self):
		
		quit_flag = False
		i=0
		while i < len(self.im_path):
			if quit_flag:
				break
			self.image = cv2.imread(self.im_path[i]).copy()
			self.new_image = None
			try:
				cv2.destroyWindow("new")
			except:
				pass
			while True:
				cv2.imshow("Image", self.image )
				ch = cv2.waitKey(1) & 0xFF
				if ch == 27:
					quit_flag = True
					print "Quit Flag is True"
					break
				elif ch == ord('s') or ch == ord("S"):
					# compute_new_image
					print "s pressed"
					if self.new_image is not None:
						cv2.imwrite(self.im_path[i], self.new_image)
						i = i + 1
					break
				elif ch == ord('d'):
					print "D key pressed.\nLoading Next image"
					i = i + 1
					break
				elif ch == ord('a'):
					print "A key pressed.\nLoading previous image"
					i = i - 1
					break



def main(argv):
	parser = argparse.ArgumentParser()
	parser.add_argument("-b", "--base_dir", type=str, default="/home/<path to images>", help="Path for base dir of images")
	parser.add_argument("-p", "--path",  type=str, default=None, help="sub-dir for images" )
	parser.add_argument("-r", "--resolution", type=str, default="1280x960", help="Image resolution")

	crop = Cropper(vars(parser.parse_args()))
	crop.run()


if __name__ == '__main__':
	main(sys.argv)