qr_read_rotate.py

import cv2
from pyzbar.pyzbar import decode
import imutils
from imutils.video import VideoStream
import os

# constants
angle_increase = 30

def getNumber(line, prop):
    numbers = []
    count = 0
    found_equal = False
    if prop in line:
        for character in line:
            if found_equal == True:
                numbers.append(line[count])
            if character == 'b':
                found_equal = True
            if character == "'" and line[count + 1] == ",":
                return numbers
            count = count + 1
        return numbers


def dataArrayToString(line, prop):
    number_string = ""
    number = getNumber(line, prop)
    if number == None:
        return ""
    for num in number:
        number_string += num
    return number_string

# save codes


def detectionFeed(robot_camera, ip):

    # grab stream
    if not robot_camera:
        source = VideoStream(src=0).start()
    else:
        source = VideoStream(src=ip).start()

    codes = {}

    while True:
        # read front camera
        im = source.read()

        # convert to grayscale
        im = cv2.cvtColor(im, cv2.COLOR_BGR2GRAY)

        # increase contrast
        contrast_image = cv2.equalizeHist(im)

        # loop over all rotations
        for angle in range(0, 360, angle_increase):

            # rotate contrast_image by angle
            rows, cols = contrast_image.shape
            M = cv2.getRotationMatrix2D((cols/2, rows/2), angle, 1)
            dst = cv2.warpAffine(contrast_image, M, (cols, rows))
            #cv2.imshow('test', dst)

            # decode QR code
            decoded = decode(dst)
            decodedString = dataArrayToString(str(decoded), "data=")

            # if theres something in the output of decoded()
            if len(decoded) == 1:

                # do the region
                [x, y, w, h] = decoded[0].rect
                [x1, y1, x2, y2] = [x, y, x+w, y+h]
                region = dst[y1:y2, x1:x2]
                #cv2.rectangle(contrast_image, (x1, y1), (x2, y2), (255), 3)
                #cv2.rectangle(contrast_image, (x1, y1), (x2, y2), (0), 1)

                # print to console, if there is not nothing (= if there is something)
                if (decodedString != ""):
                    print(decodedString)

                # add the string and the region to the codes dict
                codes[decodedString] = region

                # draw keypoints window
                #cv2.imshow("Keypoints", im)
                # draw histogram window

            # cv2.imshow("Camera", contrast_image)
            # _, jpeg = cv2.imencode('.jpg', contrast_image)
            # bytes = jpeg.tobytes()
            # yield (b'--frame\r\n'
            #     b'Content-Type: image/jpeg\r\n\r\n' + bytes + b'\r\n\r\n')
            yield bytes(decodedString)