Rotation, Mouse events, Perspectives and more...

python_opencv_camera_app.py

import cv2, time, sys
from random import *
import numpy as np
font = cv2.FONT_HERSHEY_SIMPLEX
xi, yi = 0, 0
def func(event, x, y, _, __):
	global cap, img, xi, yi
	xi, yi = x, y
	if event == cv2.EVENT_LBUTTONUP:
		___, img = cap.read()
		cap.release()
		cv2.destroyAllWindows()
downed = False
pts = list()
def rotate(event, x, y, _, __):
	global _img, wi, hi
	if event == cv2.EVENT_LBUTTONUP:
		M = cv2.getRotationMatrix2D((wi/2, hi/2),-90,1)
		_img = cv2.warpAffine(_img, M, (wi,hi))
		cv2.imshow('Result', _img)
def align(pts):
	dst = lambda pt1, pt2: ((pt1[0]-pt2[0])**2+(pt1[1]-pt2[1])**2)**0.5
	ver, hor = 0.0, 0.0
	left, right = list(), list()
	ver = sum([pt[0] for pt in pts])/4
	for pt in pts:
		if pt[0]>ver:
			right.append(pt)
		else:
			left.append(pt)
	if len(right) == len(left):
		ul, dl = left[0], left[1]
		if left[0][1]>left[1][1]:
			ul, dl = dl, ul
		ur, dr = right[0], right[1]
		if right[0][1]>right[1][1]:
			ur, dr = dr, ur
	else:
		up, down = list(), list()
		hor = sum([pt[1] for pt in pts])/4
		for pt in pts:
			if pt[1] > hor:
				down.append(pt)
			else:
				up.append(pt)
		dl, dr = down[0], down[1]
		if down[0][0]>down[1][0]:
			dl, dr = dr, dl
		ul, ur = up[0], up[1]
		if up[0][0]>up[1][0]:
			ul, ur = ur, ul
	return np.float32([ul, ur, dr, dl]), int(dst(ul, ur)), int(dst(ul, dl))
def func2(event, x, y, _, __):
	global img, w, h, downed, ix, iy, pts, _img, wi, hi
	if event == cv2.EVENT_LBUTTONDOWN:
		downed = True
		ix, iy = x, y
	elif event == cv2.EVENT_LBUTTONUP:
		downed = False
		cv2.imshow('Image', img)
	elif event == cv2.EVENT_MOUSEMOVE:
		if downed:
			M = np.float32([[1, 0, x-ix], [0, 1, y-iy]])
			cv2.imshow('Image', cv2.warpAffine(img, M, (w, h)))
	elif event == cv2.EVENT_RBUTTONUP:
		pts.append((x, y))
		cv2.circle(img, (x, y), 2, (0, 0, 255), -1)
		cv2.imshow('Image', img)
		if len(pts) == 4:
			pts, wi, hi = align(pts)
			cv2.line(img, tuple(pts[0]), tuple(pts[1]), (255, 0, 0), 2)
			cv2.line(img, tuple(pts[0]), tuple(pts[3]), (255, 0, 0), 2)
			cv2.line(img, tuple(pts[2]), tuple(pts[1]), (255, 0, 0), 2)
			cv2.line(img, tuple(pts[2]), tuple(pts[3]), (255, 0, 0), 2)
			cv2.imshow('Image', img)
			pts_ = np.float32([(0, 0), (wi, 0), (wi, hi), (0, hi)])
			M = cv2.getPerspectiveTransform(pts, pts_)
			_img = cv2.warpPerspective(img,M,(wi,hi))
			cv2.destroyWindow('Image')
			cv2.imshow('Result', _img)
			cv2.setMouseCallback('Result', rotate)
cap = cv2.VideoCapture(0)
cv2.namedWindow('Camera')
cv2.setMouseCallback('Camera', func)
w, h = int(cap.get(3)), int(cap.get(4))
pos = (15, h-20)
while cap.isOpened():
	_, frame = cap.read()
	cv2.putText(frame, 'Click to Capture IMAGE', pos, font, 1, (0, 0, 0), 2, cv2.LINE_AA)
	cv2.putText(frame, str(xi)+','+str(yi), (0, 25), font, 1, (0, 0, 0), 1, cv2.LINE_AA)
	cv2.imshow('Camera', frame)
	if cv2.waitKey(1) & 0xFF == 27:
		cap.release()
		break
cv2.namedWindow('Image')
cv2.setMouseCallback('Image', func2)
cv2.imshow('Image', img)
if cv2.waitKey(0) & 0xFF == 27:
	cv2.destroyAllWindows()