opencv/samples/python/qrcode.py
jshiwam d4fc302c7e
Merge pull request #16795 from jshiwam:qrsample
Added a sample file for qrcode detection in python

* sample python file for qrcode detection added in samples/python

* input taken using argparse and the indents were removed

* Removed unused variables

* updated the format and removed unused variables

Removed the use of global variables and used parameterised contructor instead

=set multi detection true by default

* added detection from camera

* samples(python): coding style in qrcode.py
2020-04-17 12:16:39 +00:00

249 lines
8.2 KiB
Python

#!/usr/bin/env python
'''
This program detects the QR-codes using OpenCV Library.
Usage:
qrcode.py
'''
# Python 2/3 compatibility
from __future__ import print_function
import numpy as np
import cv2 as cv
import argparse
import sys
PY3 = sys.version_info[0] == 3
if PY3:
xrange = range
class QrSample:
def __init__(self, args):
self.fname = ''
self.fext = ''
self.fsaveid = 0
self.input = args.input
self.detect = args.detect
self.out = args.out
self.multi = args.multi
self.saveDetections = args.save_detections
self.saveAll = args.save_all
def getQRModeString(self):
msg1 = "multi " if self.multi else ""
msg2 = "detector" if self.detect else "decoder"
msg = "QR {:s}{:s}".format(msg1, msg2)
return msg
def drawFPS(self, result, fps):
message = '{:.2f} FPS({:s})'.format(fps, self.getQRModeString())
cv.putText(result, message, (20, 20), 1,
cv.FONT_HERSHEY_DUPLEX, (0, 0, 255))
def drawQRCodeContours(self, image, cnt):
if cnt.size != 0:
rows, cols, _ = image.shape
show_radius = 2.813 * ((rows / cols) if rows > cols else (cols / rows))
contour_radius = show_radius * 0.4
cv.drawContours(image, [cnt], 0, (0, 255, 0), int(round(contour_radius)))
tpl = cnt.reshape((-1, 2))
for x in tuple(tpl.tolist()):
color = (255, 0, 0)
cv.circle(image, tuple(x), int(round(contour_radius)), color, -1)
def drawQRCodeResults(self, result, points, decode_info, fps):
n = len(points)
if isinstance(decode_info, str):
decode_info = [decode_info]
if n > 0:
for i in range(n):
cnt = np.array(points[i]).reshape((-1, 1, 2)).astype(np.int32)
self.drawQRCodeContours(result, cnt)
msg = 'QR[{:d}]@{} : '.format(i, *(cnt.reshape(1, -1).tolist()))
print(msg, end="")
if len(decode_info) > i:
if decode_info[i]:
print("'", decode_info[i], "'")
else:
print("Can't decode QR code")
else:
print("Decode information is not available (disabled)")
else:
print("QRCode not detected!")
self.drawFPS(result, fps)
def runQR(self, qrCode, inputimg):
if not self.multi:
if not self.detect:
decode_info, points, _ = qrCode.detectAndDecode(inputimg)
dec_info = decode_info
else:
_, points = qrCode.detect(inputimg)
dec_info = []
else:
if not self.detect:
_, decode_info, points, _ = qrCode.detectAndDecodeMulti(
inputimg)
dec_info = decode_info
else:
_, points = qrCode.detectMulti(inputimg)
dec_info = []
if points is None:
points = []
return points, dec_info
def DetectQRFrmImage(self, inputfile):
inputimg = cv.imread(inputfile, cv.IMREAD_COLOR)
if inputimg is None:
print('ERROR: Can not read image: {}'.format(inputfile))
return
print('Run {:s} on image [{:d}x{:d}]'.format(
self.getQRModeString(), inputimg.shape[1], inputimg.shape[0]))
qrCode = cv.QRCodeDetector()
count = 10
timer = cv.TickMeter()
for _ in range(count):
timer.start()
points, decode_info = self.runQR(qrCode, inputimg)
timer.stop()
fps = count / timer.getTimeSec()
print('FPS: {}'.format(fps))
result = inputimg
self.drawQRCodeResults(result, points, decode_info, fps)
cv.imshow("QR", result)
cv.waitKey(1)
if self.out != '':
outfile = self.fname + self.fext
print("Saving Result: {}".format(outfile))
cv.imwrite(outfile, result)
print("Press any key to exit ...")
cv.waitKey(0)
print("Exit")
def processQRCodeDetection(self, qrcode, frame):
if len(frame.shape) == 2:
result = cv.cvtColor(frame, cv.COLOR_GRAY2BGR)
else:
result = frame
print('Run {:s} on video frame [{:d}x{:d}]'.format(
self.getQRModeString(), frame.shape[1], frame.shape[0]))
timer = cv.TickMeter()
timer.start()
points, decode_info = self.runQR(qrcode, frame)
timer.stop()
fps = 1 / timer.getTimeSec()
self.drawQRCodeResults(result, points, decode_info, fps)
return fps, result, points
def DetectQRFrmCamera(self):
cap = cv.VideoCapture(0)
if not cap.isOpened():
print("Cannot open the camera")
return
print("Press 'm' to switch between detectAndDecode and detectAndDecodeMulti")
print("Press 'd' to switch between decoder and detector")
print("Press ' ' (space) to save result into images")
print("Press 'ESC' to exit")
qrcode = cv.QRCodeDetector()
while True:
ret, frame = cap.read()
if not ret:
print("End of video stream")
break
forcesave = self.saveAll
result = frame
try:
fps, result, corners = self.processQRCodeDetection(qrcode, frame)
print('FPS: {:.2f}'.format(fps))
forcesave |= self.saveDetections and (len(corners) != 0)
except cv.error as e:
print("Error exception: ", e)
forcesave = True
cv.imshow("QR code", result)
code = cv.waitKey(1)
if code < 0 and (not forcesave):
continue
if code == ord(' ') or forcesave:
fsuffix = '-{:05d}'.format(self.fsaveid)
self.fsaveid += 1
fname_in = self.fname + fsuffix + "_input.png"
print("Saving QR code detection result: '{}' ...".format(fname_in))
cv.imwrite(fname_in, frame)
print("Saved")
if code == ord('m'):
self.multi = not self.multi
msg = 'Switching QR code mode ==> {:s}'.format(
"detectAndDecodeMulti" if self.multi else "detectAndDecode")
print(msg)
if code == ord('d'):
self.detect = not self.detect
msg = 'Switching QR code mode ==> {:s}'.format(
"detect" if self.detect else "decode")
print(msg)
if code == 27:
print("'ESC' is pressed. Exiting...")
break
print("Exit.")
def main():
parser = argparse.ArgumentParser(
description='This program detects the QR-codes input images using OpenCV Library.')
parser.add_argument(
'-i',
'--input',
help="input image path (for example, 'opencv_extra/testdata/cv/qrcode/multiple/*_qrcodes.png)",
default="",
metavar="")
parser.add_argument(
'-d',
'--detect',
help="detect QR code only (skip decoding) (default: False)",
action='store_true')
parser.add_argument(
'-m',
'--multi',
help="enable multiple qr-codes detection",
action='store_true')
parser.add_argument(
'-o',
'--out',
help="path to result file (default: qr_code.png)",
default="qr_code.png",
metavar="")
parser.add_argument(
'--save_detections',
help="save all QR detections (video mode only)",
action='store_true')
parser.add_argument(
'--save_all',
help="save all processed frames (video mode only)",
action='store_true')
args = parser.parse_args()
qrinst = QrSample(args)
if args.out != '':
index = args.out.rfind('.')
if index != -1:
qrinst.fname = args.out[:index]
qrinst.fext = args.out[index:]
else:
qrinst.fname = args.out
qrinst.fext = ".png"
if args.input != '':
qrinst.DetectQRFrmImage(args.input)
else:
qrinst.DetectQRFrmCamera()
if __name__ == '__main__':
main()