opencv4-qr-detect-sliding-window.py

import sys

import cv2


def sliding_window(image, stepSize, windowSize):
    for y in range(0, image.shape[0], stepSize):
        for x in range(0, image.shape[1], stepSize):
            # yield the current window
            yield (x, y, image[y : y + windowSize[1], x : x + windowSize[0]])


img = cv2.imread(sys.argv[1])

qr = cv2.QRCodeDetector()
winW = int(img.shape[1] / 4)
winH = int(img.shape[0] / 4)
step = int(img.shape[1] / 5)
print("image size: {} x {} ".format(img.shape[1], img.shape[0]))
print("window size: {} x {}, step={} ".format(winW, winH, step))

for (x, y, window) in sliding_window(img, stepSize=step, windowSize=(winW, winH)):
    print(x, y, window.shape)
    if window.shape[0] != winH or window.shape[1] != winW:
        continue
    data, points, straight_qrcode = qr.detectAndDecode(window)
    cv2.imwrite("cut-{}-{}.jpg".format(x, y), window)
    if data:
        print("detected: {}".format(data))
        break

opencv4-qr-detect-with-split.py

import sys
from itertools import product

import cv2


def split(n: int, d: int):
    i = int(n / d)
    ret = [(x, x + i) for x in range(0, n, i)]
    return ret


def detect(img, divide):
    i = 0
    height = img.shape[0]
    width = img.shape[1]

    for (sx, ex), (sy, ey) in product(split(height, divide), split(width, divide)):
        print(divide, int(sx), int(ex), int(sy), int(ey))
        dst = img[int(sx) : int(ex), int(sy) : int(ey)]
        cv2.imwrite("cut-{}.jpg".format(i), dst)

        data, points, straight_qrcode = qr.detectAndDecode(dst)

        if data:
            return data
        i += 1


img = cv2.imread(sys.argv[1])

qr = cv2.QRCodeDetector()

for divide in range(1, 4):
    data = detect(img, divide)
    if data:
        print("データ:", data)