无法处理解码的图像文件、Flask、OpenCV

Question

我通过客户端文件接收到flask 应用程序的一堆图像。

client.py

# Generate the parallel requests based on the ThreadPool Executor
from concurrent.futures import ThreadPoolExecutor as PoolExecutor
import sys
import time
import glob
import requests
import threading
import uuid
import base64
import  json
import os

#send http request
def call_object_detection_service(image):
    try:

        url = str(sys.argv[2])
        data = {}
        #generate uuid for image
        id = uuid.uuid5(uuid.NAMESPACE_OID, image)
        # Encode image into base64 string
        with open (image, 'rb') as image_file:
            data['image'] =  base64.b64encode(image_file.read()).decode('utf-8')

        data['id'] = str(id)
        headers = {'Content-Type': 'application/json'}

        response = requests.post(url, json= json.dumps(data), headers = headers)

        if response.ok:
            output = "Thread : {},  input image: {},  output:{}".format(threading.current_thread().getName(),
                                                                        image,  response.text)
            print(output)
        else:
            print ("Error, response status:{}".format(response))

    except Exception as e:
        print("Exception in webservice call: {}".format(e))

# gets list of all images path from the input folder
def get_images_to_be_processed(input_folder):
    images = []
    for image_file in glob.iglob(input_folder + "*.jpg"):
        images.append(image_file)
    return images

def main():
    ## provide argumetns-> input folder, url, number of wrokers
    if len(sys.argv) != 4:
        raise ValueError("Arguments list is wrong. Please use the following format: {} {} {} {}".
                         format("python iWebLens_client.py", "<input_folder>", "<URL>", "<number_of_workers>"))

    input_folder = os.path.join(sys.argv[1], "")
    images = get_images_to_be_processed(input_folder)
    num_images = len(images)
    num_workers = int(sys.argv[3])
    start_time = time.time()
    #craete a worker  thread  to  invoke the requests in parallel
    with PoolExecutor(max_workers=num_workers) as executor:
        for _ in executor.map(call_object_detection_service,  images):
            pass
    #elapsed_time =  time.time() - start_time
    #print("Total time spent: {} average response time: {}".format(elapsed_time, elapsed_time/num_images))


if __name__ == "__main__":
    main()

我像这样解码它们 烧瓶应用

app = Flask(__name__)

c = 1
@app.route('/api/object_detection', methods = ['POST'])
def main():
    global c
    try:
        data = request.get_json(force=True)
        uid = data.get('id')
        image = data.get('image')
        print(image)
        im = base64.decodebytes(image)
        with open("image{}".format(c), 'wb') as f:
            f.write(im)
        c += 1
        for l in range(128):
            img = cv2.imread("image{}".format(l), cv2.IMREAD_ANYCOLOR);
            # load the neural net.  Should be local to this method as its multi-threaded endpoint
            nets = load_model(CFG, Weights)
            s = do_prediction(img, nets, Lables)
            return jsonify(s)

    except Exception as e:
        print(e)




if __name__ == '__main__':
    app.run(host='0.0.0.0', debug=True, threaded=True)

这会创建不同大小的图像文件，但我无法在图像查看器中查看它们。收到的文件是jpg 文件。忽略这一点，我继续处理，我得到了

TypeError: The view function for 'main' did not return a valid response. The function either returned None or ended without a return statement.
Incorrect padding
Incorrect padding
[INFO] loading YOLO from disk...
'NoneType' object has no attribute 'shape'

图片是这样发送的。

python iWebLens_client.py inputfolder/ http://192.168.29.75:5000/api/object_detection 4

图像是这样接收的。

b'"{\\"image\\": \\"/9j/4AAQSkZJRgABAQEASABIAAD/4gxYSUNDX1BST0ZJTEUAAQEAAAxITGlubwIQAABtbnRyUkdCIFhZWiAHzgACAAkABgAxAABhY3NwTVNGVAAAAABJRUMgc1JHQgAAAAAAAAAAAAAAAAAA......fiU05tQopHNf//Z\\", \\"id\\": \\"e3ad9809-b84c-57f1-bd03-a54e25c59bcc\\"}"'

我想我需要decode('utf-8') 这个，但不知道怎么做。

Answer 1

目前，您在客户端对数据进行双重编码。在请求中，传递的参数已经转换为 JSON。

只需将 dict 作为 json 参数传递。

def call_object_detection_service(image):
    try:

        url = str(sys.argv[2])
        data = {}
        #generate uuid for image
        id = uuid.uuid5(uuid.NAMESPACE_OID, image)
        # Encode image into base64 string
        with open (image, 'rb') as image_file:
            data['image'] =  base64.b64encode(image_file.read()).decode('utf-8')

        data['id'] = str(id)
        headers = {'Content-Type': 'application/json'}

        # HERE IS THE CHANGE !!!
        response = requests.post(url, json=data, headers=headers)

        if response.ok:
            output = "Thread : {},  input image: {},  output:{}".format(
                threading.current_thread().getName(),
                image, 
                response.text
            )
            print(output)
        else:
            print ("Error, response status:{}".format(response))

    except Exception as e:
        print("Exception in webservice call: {}".format(e))

现在可以在服务器上以 JSON 格式接收数据并提取到字典中。

@app.route('/api/object_detection', methods=['POST'])
def main():
    data = request.get_json(force=True)
    uid = data.get('id')
    image = data.get('image')
    # ... decode the base64 data here ...
    return jsonify(message='done')