如何使用网络摄像头解码 Datamatrix？

Question

我已从图像中读取数据矩阵，现在正尝试从网络摄像头读取该数据，但它无法正常工作，并且我不断收到错误消息。我已经尝试从 pyimagesearch 站点进行条形码/二维码检测。

我使用了 Zbar 库，它运行良好，但不支持 datamatrix。现在我正在尝试使用 pylibdmtx，它适用于图像但滞后并且无法在视频中检测到。

代码 1

from imutils.video import VideoStream
from pyzbar import pyzbar
from pydmtx import DataMatrix
import zxing
import argparse
import datetime
import imutils
import time
import cv2

# construct the argument parser and parse the arguments
ap = argparse.ArgumentParser()
reader = zxing.BarCodeReader("/home/creator/.local/bin/zxing")
ap.add_argument("-o", "--output", type=str, default="barcodes.csv",
    help="path to output CSV file containing barcodes")
args = vars(ap.parse_args())

# initialize the video stream and allow the camera sensor to warm up
print("[INFO] starting video stream...")
vs = VideoStream(src=0).start()
# vs = VideoStream(usePiCamera=True).start()
time.sleep(2.0)

# open the output CSV file for writing and initialize the set of
# barcodes found thus far
csv = open(args["output"], "w")
found = set()


# loop over the frames from the video stream
while True:
    # grab the frame from the threaded video stream and resize it to
    # have a maximum width of 400 pixels
    frame = vs.read()
    frame = imutils.resize(frame, width=40)

    # find the barcodes in the frame and decode each of the barcodes
    barcodes = pylibdmtx.decode(frame)

        # loop over the detected barcodes
    for barcode in barcodes:
        # extract the bounding box location of the barcode and draw
        # the bounding box surrounding the barcode on the image
        (x, y, w, h) = barcode.rect
        cv2.rectangle(frame, (x, y), (x + w, y + h), (0, 0, 255), 2)

        # the barcode data is a bytes object so if we want to draw it
        # on our output image we need to convert it to a string first
        barcodeData = barcode.data.decode("utf-8")
        barcodeType = barcode.type
        print("Data :",barcodeData,'\n')
        print("Type :",barcodeType)

        # draw the barcode data and barcode type on the image
        text = "{} ({})".format(barcodeData, barcodeType)
        cv2.putText(frame, text, (x, y - 10),
            cv2.FONT_HERSHEY_SIMPLEX, 0.5, (0, 0, 255), 2)


        # if the barcode text is currently not in our CSV file, write
        # the timestamp + barcode to disk and update the set
        if barcodeData not in found:
            csv.write("{},{}\n".format(datetime.datetime.now(),
                barcodeData))
            csv.flush()
            found.add(barcodeData)

    # show the output frame
    cv2.imshow("Barcode Scanner", frame)
    key = cv2.waitKey(1) & 0xFF

    # if the `q` key was pressed, break from the loop
    if key == ord("q"):
        break

# close the output CSV file do a bit of cleanup
print("[INFO] cleaning up...")
csv.close()
cv2.destroyAllWindows()
vs.stop()

代码 1 运行，但速度太慢，没有检测到任何东西。

结果：应该在相机上显示读取数据矩阵。

Answer 1

• 将第 3 行更改为：

从 pylibdmtx 导入 pylibdmtx

• 因为我没有 zxing，所以我在代码中注释了那些行（4 和 13）。

• Datamatrix 解码器没有像条码解码器这样的类型。因此将第 52 行更改如下：

  barcodeType = "DMC" #barcode.type

• 添加了一条打印语句以查看循环内的解码输出，如下所示：

对于条形码中的条形码：

    print(barcode)

输出：

类型：DMC 解码（数据=b'800400547311010400109085566'，矩形=矩形（左=241，顶部=238，宽度=65，高度=-83）） 数据：800400547311010400109085566

类型：DMC 解码（数据=b'800040547311010400102325376'，矩形=矩形（左=259，顶部=140，宽度=-119，高度=110）） 数据：800040547311010400102325376

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请有人帮忙解决缓慢的问题，因为我找不到原因。

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