Add a YOLO example

Author: yushulx

examples/official/9.x/yolo_qr/416x416.jpg

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+# QR Detection with OpenCV and YOLO Model in Python
+This repository provides samples demonstrating how to detect QR codes using **YOLO** and how to read QR codes with the [Dynamsoft Barcode Reader](https://www.dynamsoft.com/barcode-reader/overview/).
+
+## Prerequisites
+- OpenCV 4.x
+    
+    ```
+    pip install opencv-python
+    ```
+
+- Dynamsoft Barcode Reader
+
+    ```
+    pip install dbr
+    ```
+- Obtain a [Dynamsoft Barcode Reader trial license](https://www.dynamsoft.com/customer/license/trialLicense?product=dbr) and update your code with the provided license key:
+    
+    ```python
+    from dbr import *
+
+    license_key = "LICENSE-KEY"
+    BarcodeReader.init_license(license_key)
+    reader = BarcodeReader()
+    ```
+    
+
+## Usage
+
+#### QR Detection
+
+- From Image File:
+
+    ```
+    python3 opencv-yolo.py
+    ```
+
+- From Camera:
+
+    ```
+    python3 opencv-yolo-camera.py
+    ```
+
+    ![OpenCV YOLO for QR detection](https://www.dynamsoft.com/codepool/img/2020/11/opencv-dnn-yolo3-qr-detection.gif)
+
+#### QR Reading with Dynamsoft Barcode Reader
+
+Below is a sample code snippet for reading QR codes with the Dynamsoft Barcode Reader:
+
+```py
+from dbr import *
+
+license_key = "LICENSE-KEY"
+BarcodeReader.init_license(license_key)
+reader = BarcodeReader()
+settings = reader.reset_runtime_settings() 
+settings = reader.get_runtime_settings()
+settings.region_bottom  = bottom
+settings.region_left    = left
+settings.region_right   = right
+settings.region_top     = top
+reader.update_runtime_settings(settings)
+
+try:
+    text_results = reader.decode_buffer(frame)
+
+    if text_results != None:
+        for text_result in text_results:
+            print("Barcode Format :")
+            print(text_result.barcode_format_string)
+            print("Barcode Text :")
+            print(text_result.barcode_text)
+            print("Localization Points : ")
+            print(text_result.localization_result.localization_points)
+            print("-------------")
+except BarcodeReaderError as bre:
+    print(bre)
+```
+
+- From Image File:
+
+    ```
+    python3 yolo-dbr.py
+    ```
+
+- From Camera:
+
+    ```
+    python3 yolo-dbr-camera.py
+    ```
+
+## Blog
+[How to Detect and Decode QR Code with YOLO, OpenCV, and Dynamsoft Barcode Reader](https://www.dynamsoft.com/codepool/qr-code-detect-decode-yolo-opencv.html)

examples/official/9.x/yolo_qr/README.md

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+from time import sleep
+import cv2 as cv
+import numpy as np
+import time
+from threading import Thread
+import queue
+from dbr import *
+
+license_key = "DLS2eyJoYW5kc2hha2VDb2RlIjoiMjAwMDAxLTE2NDk4Mjk3OTI2MzUiLCJvcmdhbml6YXRpb25JRCI6IjIwMDAwMSIsInNlc3Npb25QYXNzd29yZCI6IndTcGR6Vm05WDJrcEQ5YUoifQ=="
+BarcodeReader.init_license(license_key)
+reader = BarcodeReader()
+color = (0, 0, 255)
+thickness = 2
+
+
+def decodeframe(frame):
+
+    try:
+        outs = reader.decode_buffer(frame)
+        if outs != None:
+            return outs
+    except BarcodeReaderError as bre:
+        print(bre)
+
+    return None
+
+
+winName = 'QR Detection'
+
+
+def postprocess(frame, outs):
+    if outs == None:
+        return
+
+    for out in outs:
+        points = out.localization_result.localization_points
+
+        cv.line(frame, points[0], points[1], color, thickness)
+        cv.line(frame, points[1], points[2], color, thickness)
+        cv.line(frame, points[2], points[3], color, thickness)
+        cv.line(frame, points[3], points[0], color, thickness)
+        cv.putText(frame, out.barcode_text, (min([point[0] for point in points]), min(
+            [point[1] for point in points])), cv.FONT_HERSHEY_SIMPLEX, 1, color, thickness)
+
+
+cap = cv.VideoCapture(0)
+
+
+class QueueFPS(queue.Queue):
+    def __init__(self):
+        queue.Queue.__init__(self)
+        self.startTime = 0
+        self.counter = 0
+
+    def put(self, v):
+        queue.Queue.put(self, v)
+        self.counter += 1
+        if self.counter == 1:
+            self.startTime = time.time()
+
+    def getFPS(self):
+        return self.counter / (time.time() - self.startTime)
+
+
+process = True
+
+#
+# Frames capturing thread
+#
+framesQueue = QueueFPS()
+
+
+def framesThreadBody():
+    global framesQueue, process
+
+    while process:
+        hasFrame, frame = cap.read()
+        if not hasFrame:
+            break
+        framesQueue.put(frame)
+
+
+#
+# Frames processing thread
+#
+decodingQueue = QueueFPS()
+
+
+def processingThreadBody():
+    global decodingQueue, process
+
+    while process:
+        # Get a next frame
+        frame = None
+        try:
+            frame = framesQueue.get_nowait()
+            framesQueue.queue.clear()
+        except queue.Empty:
+            pass
+
+        if not frame is None:
+            outs = decodeframe(frame)
+            decodingQueue.put((frame, outs))
+            sleep(0.03)
+
+
+framesThread = Thread(target=framesThreadBody)
+framesThread.start()
+
+processingThread = Thread(target=processingThreadBody)
+processingThread.start()
+
+#
+# Postprocessing and rendering loop
+#
+while cv.waitKey(1) < 0:
+    try:
+        # Request prediction first because they put after frames
+        outs = decodingQueue.get_nowait()
+        frame = outs[0]
+        postprocess(frame, outs[1])
+
+        # Put efficiency information.
+        if decodingQueue.counter > 1:
+            label = 'Camera: %.2f FPS' % (framesQueue.getFPS())
+            cv.putText(frame, label, (0, 15),
+                       cv.FONT_HERSHEY_SIMPLEX, 0.5, (0, 255, 0))
+
+            label = 'DBR SDK: %.2f FPS' % (decodingQueue.getFPS())
+            cv.putText(frame, label, (0, 30),
+                       cv.FONT_HERSHEY_SIMPLEX, 0.5, (0, 255, 0))
+
+            label = 'Skipped frames: %d' % (
+                framesQueue.counter - decodingQueue.counter)
+            cv.putText(frame, label, (0, 45),
+                       cv.FONT_HERSHEY_SIMPLEX, 0.5, (0, 255, 0))
+
+        cv.imshow(winName, frame)
+    except queue.Empty:
+        pass
+
+
+process = False
+framesThread.join()
+processingThread.join()

examples/official/9.x/yolo_qr/cropped.jpg

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+import cv2 as cv
+import numpy as np
+import time
+from dbr import *
+
+license_key = "DLS2eyJoYW5kc2hha2VDb2RlIjoiMjAwMDAxLTE2NDk4Mjk3OTI2MzUiLCJvcmdhbml6YXRpb25JRCI6IjIwMDAwMSIsInNlc3Npb25QYXNzd29yZCI6IndTcGR6Vm05WDJrcEQ5YUoifQ=="
+BarcodeReader.init_license(license_key)
+reader = BarcodeReader()
+color = (0, 0, 255)
+thickness = 2
+
+
+def decodeframe(frame):
+
+    try:
+        text_results = reader.decode_buffer(frame)
+
+        if text_results != None:
+            for text_result in text_results:
+                print("Barcode Format :")
+                print(text_result.barcode_format_string)
+                print("Barcode Text :")
+                print(text_result.barcode_text)
+                print("Localization Points : ")
+                print(text_result.localization_result.localization_points)
+                print("-------------")
+                points = text_result.localization_result.localization_points
+
+                cv.line(frame, points[0], points[1], color, thickness)
+                cv.line(frame, points[1], points[2], color, thickness)
+                cv.line(frame, points[2], points[3], color, thickness)
+                cv.line(frame, points[3], points[0], color, thickness)
+
+                cv.putText(frame, text_result.barcode_text, (min([point[0] for point in points]), min(
+                    [point[1] for point in points])), cv.FONT_HERSHEY_SIMPLEX, 1, color, thickness)
+    except BarcodeReaderError as bre:
+        print(bre)
+
+
+# Load an frame
+frame = cv.imread("416x416.jpg")
+decodeframe(frame)
+
+cv.imshow('QR Detection', frame)
+cv.waitKey()