Python cv2.imshow() Examples

def __get_annotation__(self, mask, image=None):

        _, contours, _ = cv2.findContours(mask, cv2.RETR_TREE, cv2.CHAIN_APPROX_SIMPLE)

        segmentation = []
        for contour in contours:
            # Valid polygons have >= 6 coordinates (3 points)
            if contour.size >= 6:
                segmentation.append(contour.flatten().tolist())
        RLEs = cocomask.frPyObjects(segmentation, mask.shape[0], mask.shape[1])
        RLE = cocomask.merge(RLEs)
        # RLE = cocomask.encode(np.asfortranarray(mask))
        area = cocomask.area(RLE)
        [x, y, w, h] = cv2.boundingRect(mask)

        if image is not None:
            image = cv2.cvtColor(image, cv2.COLOR_RGB2BGR)
            cv2.drawContours(image, contours, -1, (0,255,0), 1)
            cv2.rectangle(image,(x,y),(x+w,y+h), (255,0,0), 2)
            cv2.imshow("", image)
            cv2.waitKey(1)

        return segmentation, [x, y, w, h], area 

def _lapulaseDetection(self, imgName):
        """
        :param strdir: 文件所在的目录
        :param name: 文件名称
        :return: 检测模糊后的分数
        """
        # step1: 预处理
        img2gray, reImg = self.preImgOps(imgName)
        # step2: laplacian算子 获取评分
        resLap = cv2.Laplacian(img2gray, cv2.CV_64F)
        score = resLap.var()
        print("Laplacian %s score of given image is %s", str(score))
        # strp3: 绘制图片并保存  不应该写在这里  抽象出来   这是共有的部分
        newImg = self._drawImgFonts(reImg, str(score))
        newDir = self.strDir + "/_lapulaseDetection_/"
        if not os.path.exists(newDir):
            os.makedirs(newDir)
        newPath = newDir + imgName
        # 显示
        cv2.imwrite(newPath, newImg)  # 保存图片
        cv2.imshow(imgName, newImg)
        cv2.waitKey(0)

        # step3: 返回分数
        return score 

def run(self):
        print("VEDIO server starts...")
        self.sock.bind(self.ADDR)
        self.sock.listen(1)
        conn, addr = self.sock.accept()
        print("remote VEDIO client success connected...")
        data = "".encode("utf-8")
        payload_size = struct.calcsize("L")
        cv2.namedWindow('Remote', cv2.WINDOW_AUTOSIZE)
        while True:
            while len(data) < payload_size:
                data += conn.recv(81920)
            packed_size = data[:payload_size]
            data = data[payload_size:]
            msg_size = struct.unpack("L", packed_size)[0]
            while len(data) < msg_size:
                data += conn.recv(81920)
            zframe_data = data[:msg_size]
            data = data[msg_size:]
            frame_data = zlib.decompress(zframe_data)
            frame = pickle.loads(frame_data)
            cv2.imshow('Remote', frame)
            if cv2.waitKey(1) & 0xFF == 27:
                break 

def live_undistort(camera, camera_matrix, distortion_coefficients):
    """ Using a given calibration matrix, display the distorted, undistorted, and cropped frame"""
    scaled_camera_matrix, roi = cv2.getOptimalNewCameraMatrix(
        camera_matrix, distortion_coefficients, camera.size, 1, camera.size
    )
    while True:
        ret, frame = camera.cap.read()
        assert ret
        distorted_frame = cv2.cvtColor(frame, cv2.COLOR_BGR2GRAY)
        undistorted_frame = cv2.undistort(
            distorted_frame, camera_matrix, distortion_coefficients, None, scaled_camera_matrix,
        )
        roi_x, roi_y, roi_w, roi_h = roi
        cropped_frame = undistorted_frame[roi_y : roi_y + roi_h, roi_x : roi_x + roi_w]
        cv2.imshow("distorted %s" % (distorted_frame.shape,), distorted_frame)
        cv2.imshow("undistorted %s" % (undistorted_frame.shape,), undistorted_frame)
        cv2.imshow("cropped %s" % (cropped_frame.shape,), cropped_frame)
        cv2.waitKey(10) 

def detect(imgfile):
    origimg = cv2.imread(imgfile)
    img = preprocess(origimg)
    
    img = img.astype(np.float32)
    img = img.transpose((2, 0, 1))

    net.blobs['data'].data[...] = img
    out = net.forward() 
    box, conf, cls = postprocess(origimg, out)

    for i in range(len(box)):
       p1 = (box[i][0], box[i][1])
       p2 = (box[i][2], box[i][3])
       cv2.rectangle(origimg, p1, p2, (0,255,0))
       p3 = (max(p1[0], 15), max(p1[1], 15))
       title = "%s:%.2f" % (COCO_CLASSES[int(cls[i])], conf[i])
       cv2.putText(origimg, title, p3, cv2.FONT_ITALIC, 0.6, (0, 255, 0), 1)
    cv2.imshow("SSD", origimg)
 
    k = cv2.waitKey(0) & 0xff
        #Exit if ESC pressed
    if k == 27 : return False
    return True 

def show2(im, allobj):
    for obj in allobj:
        cv2.rectangle(im,
            (obj[1], obj[2]), 
            (obj[3], obj[4]), 
            (0,0,255),2)
    cv2.imshow('result', im)
    cv2.waitKey()
    cv2.destroyAllWindows() 

def test():
	"""
	read the pickle file on disk and implement undistor on image
	show the oringal/undistort image
	"""
	print("Reading the pickle file...")
	pickle_file = open("./camera_cal.p", "rb")
	dist_pickle = pickle.load(pickle_file)
	mtx = dist_pickle["mtx"]  
	dist = dist_pickle["dist"]
	pickle_file.close()

	print("Reading the sample image...")
	img = cv2.imread('corners_founded/corners_found13.jpg')
	img_size = (img.shape[1],img.shape[0])
	dst = cv2.undistort(img, mtx, dist, None, mtx)

	# dst = cv2.cvtColor(dst, cv2.COLOR_BGR2GRAY)
	# Visualize undistortion
	print("Visulize the result...")
	f, (ax1,ax2) = plt.subplots(1,2, figsize=(20,10))
	ax1.imshow(img), ax1.set_title('Original Image', fontsize=15)
	ax2.imshow(dst), ax2.set_title('Undistored Image', fontsize=15)
	plt.show() 

def show(im, allobj, S, w, h, cellx, celly):
    for obj in allobj:
        a = obj[5] % S
        b = obj[5] // S
        cx = a + obj[1]
        cy = b + obj[2]
        centerx = cx * cellx
        centery = cy * celly
        ww = obj[3]**2 * w
        hh = obj[4]**2 * h
        cv2.rectangle(im,
            (int(centerx - ww/2), int(centery - hh/2)),
            (int(centerx + ww/2), int(centery + hh/2)),
            (0,0,255), 2)
    cv2.imshow('result', im)
    cv2.waitKey()
    cv2.destroyAllWindows() 

def show(im, allobj, S, w, h, cellx, celly):
    for obj in allobj:
        a = obj[5] % S
        b = obj[5] // S
        cx = a + obj[1]
        cy = b + obj[2]
        centerx = cx * cellx
        centery = cy * celly
        ww = obj[3]**2 * w
        hh = obj[4]**2 * h
        cv2.rectangle(im,
            (int(centerx - ww/2), int(centery - hh/2)),
            (int(centerx + ww/2), int(centery + hh/2)),
            (0,0,255), 2)
    cv2.imshow('result', im)
    cv2.waitKey()
    cv2.destroyAllWindows() 

def show(im, allobj, S, w, h, cellx, celly):
    for obj in allobj:
        a = obj[5] % S
        b = obj[5] // S
        cx = a + obj[1]
        cy = b + obj[2]
        centerx = cx * cellx
        centery = cy * celly
        ww = obj[3]**2 * w
        hh = obj[4]**2 * h
        cv2.rectangle(im,
            (int(centerx - ww/2), int(centery - hh/2)),
            (int(centerx + ww/2), int(centery + hh/2)),
            (0,0,255), 2)
    cv2.imshow('result', im)
    cv2.waitKey()
    cv2.destroyAllWindows() 

def main():
	#IMG PATHS
	imagePath = "test3.jpg"
	cascPath = "cascades/haarcascade_pedestrian.xml"

	pplCascade = cv2.CascadeClassifier(cascPath)
	image = cv2.imread(imagePath)
	gray = cv2.cvtColor(image, cv2.COLOR_BGR2GRAY)
	
	gray = normalize_grayimage(gray)
	 
	pedestrians = pplCascade.detectMultiScale(
		gray,
		scaleFactor=1.2,
		minNeighbors=10,
		minSize=(32,96),
		flags = cv2.cv.CV_HAAR_SCALE_IMAGE
	)

	print "Found {0} ppl!".format(len(pedestrians))

	#Draw a rectangle around the detected objects
	for (x, y, w, h) in pedestrians:
		cv2.rectangle(image, (x, y), (x+w, y+h), (0, 255, 0), 2)

	cv2.imwrite("saida.jpg", image)
	cv2.imshow("Ppl found", image)
	cv2.waitKey(0)
	
	return 0 

def detect(imgfile):
    origimg = cv2.imread(imgfile)
    img = preprocess(origimg)
    
    img = img.astype(np.float32)
    img = img.transpose((2, 0, 1))

    net.blobs['data'].data[...] = img
    out = net.forward() 
    box, conf, cls = postprocess(origimg, out)

    for i in range(len(box)):
       p1 = (box[i][0], box[i][1])
       p2 = (box[i][2], box[i][3])
       cv2.rectangle(origimg, p1, p2, (0,255,0))
       p3 = (max(p1[0], 15), max(p1[1], 15))
       title = "%s:%.2f" % (CLASSES[int(cls[i])], conf[i])
       cv2.putText(origimg, title, p3, cv2.FONT_ITALIC, 0.6, (0, 255, 0), 1)
    cv2.imshow("SSD", origimg)
 
    k = cv2.waitKey(0) & 0xff
        #Exit if ESC pressed
    if k == 27 : return False
    return True 

def _SMD2Detection(self, imgName):
        """
        灰度方差乘积
        :param imgName:
        :return:
        """
        # step 1 图像的预处理
        img2gray, reImg = self.preImgOps(imgName)
        f=self._imageToMatrix(img2gray)/255.0
        x, y = f.shape
        score = 0
        for i in range(x - 1):
            for j in range(y - 1):
                score += np.abs(f[i+1,j]-f[i,j])*np.abs(f[i,j]-f[i,j+1])
        # strp3: 绘制图片并保存  不应该写在这里  抽象出来   这是共有的部分
        score=score
        newImg = self._drawImgFonts(reImg, str(score))
        newDir = self.strDir + "/_SMD2Detection_/"
        if not os.path.exists(newDir):
            os.makedirs(newDir)
        newPath = newDir + imgName
        cv2.imwrite(newPath, newImg)  # 保存图片
        cv2.imshow(imgName, newImg)
        cv2.waitKey(0)
        return score 

def processFrames(self):
        try:
            for img in self.anotations_list:
                img = img.split(';')
                # print(img)
                # ret,imgcv = cap.read()
                if self.video:
                    ret,imgcv = self.cap.read()
                else:
                    imgcv = cv2.imread(os.path.join('../',self.config["dataset"],img[0]))
                result = self.tfnet.return_predict(imgcv)
                print(result)
                imgcv = self.drawBoundingBox(imgcv,result)        
                cv2.imshow('detected objects',imgcv)
                if cv2.waitKey(10) == ord('q'):
                    print('exitting loop')
                    break
        except KeyboardInterrupt:
            cv2.destroyAllWindows()
            print('exitting program') 

def _Variance(self, imgName):
        """
               灰度方差乘积
               :param imgName:
               :return:
               """
        # step 1 图像的预处理
        img2gray, reImg = self.preImgOps(imgName)
        f = self._imageToMatrix(img2gray)

        # strp3: 绘制图片并保存  不应该写在这里  抽象出来   这是共有的部分
        score = np.var(f)
        newImg = self._drawImgFonts(reImg, str(score))
        newDir = self.strDir + "/_Variance_/"
        if not os.path.exists(newDir):
            os.makedirs(newDir)
        newPath = newDir + imgName
        cv2.imwrite(newPath, newImg)  # 保存图片
        cv2.imshow(imgName, newImg)
        cv2.waitKey(0)
        return score 

def show2(im, allobj):
    for obj in allobj:
        cv2.rectangle(im,
            (obj[1], obj[2]), 
            (obj[3], obj[4]), 
            (0,0,255),2)
    cv2.imshow('result', im)
    cv2.waitKey()
    cv2.destroyAllWindows() 

def face_process():
    myprint("face process start",time.time())
    # Find all the faces and face encodings in the current frame of video
    # face_locations = face_recognition.face_locations(rgb_small_frame, model="cnn")
    myprint('face_locations start', time.time())
    face_locations = face_recognition.face_locations(rgb_small_frame, model="hog")
    myprint('face_locations end', time.time())
    myprint('face_encodings start', time.time())
    face_encodings = face_recognition.face_encodings(rgb_small_frame, face_locations)
    myprint('face_encodings end', time.time())
    face_names = []
    for face_encoding in face_encodings:
        # optimize start 采用KNN 排名*权重, 在类别上进行叠加,然后排序取出top1
        name, dis = vote_class(face_encoding)
        # optimize end 采用 排名*权重, 在类别上进行叠加,然后排序取出top1
        face_names.append(name)  # 将人脸数据

    # Display the results
    for (top, right, bottom, left), name in zip(face_locations, face_names):
        # Scale back up face locations since the frame we detected in was scaled to 1/4 size
        top *= 4
        right *= 4
        bottom *= 4
        left *= 4
        myprint('putText start', time.time())
        # Draw a box around the face
        cv2.rectangle(frame, (left, top), (right, bottom), (0, 0, 255), 2)
        # Draw a label with a name below the face
        cv2.rectangle(frame, (left, bottom - 35), (right, bottom), (0, 0, 255), cv2.FILLED)
        font = cv2.FONT_HERSHEY_DUPLEX
        cv2.putText(frame, name, (left + 6, bottom - 6), font, 1.0, (255, 255, 255), 1)
        myprint("putText end " + name, time.time())
        # say hello and save record to file
        myprint('process_face_records start', time.time())
        process_face_records(name)
        myprint('process_face_records end', time.time())

    # Display the resulting image
    cv2.imshow('Video', frame)
    myprint("face process end", time.time()) 

def update(self, radarData):
        self.img = np.zeros((self.height, self.width, self.channels), np.uint8)
        cv2.line(self.img, (10, 0), (self.width/2 - 5, self.height), (100, 255, 255))
        cv2.line(self.img, (self.width - 10, 0), (self.width/2 + 5, self.height), (100, 255, 255))

        for track_number in range(1, 65):
            if str(track_number)+'_track_range' in radarData:
                track_range = radarData[str(track_number)+'_track_range']
                track_angle = (float(radarData[str(track_number)+'_track_angle'])+90.0)*math.pi/180

                x_pos = math.cos(track_angle)*track_range*4
                y_pos = math.sin(track_angle)*track_range*4

                cv2.circle(self.img, (self.width/2 + int(x_pos), self.height - int(y_pos) - 10), 5, (255, 255, 255))
                #cv2.putText(self.img, str(track_number), 
                #    (self.width/2 + int(x_pos)-2, self.height - int(y_pos) - 10), self.font, 1, (255,255,255), 2)

        cv2.imshow("Radar", self.img)
        cv2.waitKey(2) 

def draw():
    f = open(box_path + 'jpglist.txt')

    # read each image and its label
    line = f.readline()
    line_num =0
    while line:
        line_num=line_num+1
        print('Image:', line_num)
        name = line.strip('\n')
        img = cv2.imread(image_path + name)
        img_size = img.shape
        img_size = img_size[0]*img_size[1]

        # read each coordinate and draw box
        f_txt = open(image_path + name.strip('.jpg') + '.txt')
        #line_txt = f_txt.readline()  # pass the first ROI information
        line_txt = f_txt.readline()
        while line_txt:
            coor = line_txt.split(',')
            x1 = int(coor[0].strip('\''))
            y1 = int(coor[1].strip('\''))
            x3 = int(coor[4].strip('\''))
            y3 = int(coor[5].strip('\''))
            text = coor[8].strip('\n').strip('\'')
            text_show = text + '(' + str(x1) + ',' + str(y1) +')'

            cv2.rectangle(img, (x1, y1), (x3, y3), (255, 0, 0), 1)
            #cv2.putText(img, text_show, (x1, y1 - 1),
              #          cv2.FONT_HERSHEY_TRIPLEX, 0.35, (0, 0, 255), 1)
            line_txt = f_txt.readline()
        cv2.imwrite(box_path + name, img)
        line = f.readline()
        # img = cv2.imshow('image', img)
        # cv2.waitKey(0) 

def show_yuv_frame(self, window_name, yuv_frame):
        # the VideoFrame.info() dictionary contains some useful information
        # such as the video resolution
        info = yuv_frame.info()
        height, width = info["yuv"]["height"], info["yuv"]["width"]

        # yuv_frame.vmeta() returns a dictionary that contains additional
        # metadata from the drone (GPS coordinates, battery percentage, ...)

        # convert pdraw YUV flag to OpenCV YUV flag
        cv2_cvt_color_flag = {
            olympe.PDRAW_YUV_FORMAT_I420: cv2.COLOR_YUV2BGR_I420,
            olympe.PDRAW_YUV_FORMAT_NV12: cv2.COLOR_YUV2BGR_NV12,
        }[info["yuv"]["format"]]

        # yuv_frame.as_ndarray() is a 2D numpy array with the proper "shape"
        # i.e (3 * height / 2, width) because it's a YUV I420 or NV12 frame

        # Use OpenCV to convert the yuv frame to RGB
        cv2frame = cv2.cvtColor(yuv_frame.as_ndarray(), cv2_cvt_color_flag)
        # Use OpenCV to show this frame
        cv2.imshow(window_name, cv2frame)
        cv2.waitKey(1)  # please OpenCV for 1 ms... 

def update(self, radarData):
        self.img = np.zeros((self.height, self.width, self.channels), np.uint8)
        cv2.line(self.img, (10, 0), (self.width/2 - 5, self.height), (100, 255, 255))
        cv2.line(self.img, (self.width - 10, 0), (self.width/2 + 5, self.height), (100, 255, 255))

        for track_number in range(1, 65):
            if str(track_number)+'_track_range' in radarData:
                track_range = radarData[str(track_number)+'_track_range']
                track_angle = (float(radarData[str(track_number)+'_track_angle'])+90.0)*math.pi/180

                x_pos = math.cos(track_angle)*track_range*4
                y_pos = math.sin(track_angle)*track_range*4

                cv2.circle(self.img, (self.width/2 + int(x_pos), self.height - int(y_pos) - 10), 5, (255, 255, 255))
                #cv2.putText(self.img, str(track_number), 
                #    (self.width/2 + int(x_pos)-2, self.height - int(y_pos) - 10), self.font, 1, (255,255,255), 2)

        cv2.imshow("Radar", self.img)
        cv2.waitKey(2) 

def _blurDetection(self, imgName):

        # step 1 图像的预处理
        img2gray, reImg = self.preImgOps(imgName)
        imgMat=self._imageToMatrix(img2gray)/255.0
        x, y = imgMat.shape
        score = 0
        for i in range(x - 2):
            for j in range(y - 2):
                score += (imgMat[i + 2, j] - imgMat[i, j]) ** 2
        # step3: 绘制图片并保存  不应该写在这里  抽象出来   这是共有的部分
        score=score/10
        newImg = self._drawImgFonts(reImg, str(score))
        newDir = self.strDir + "/_blurDetection_/"
        if not os.path.exists(newDir):
            os.makedirs(newDir)
        newPath = newDir + imgName
        cv2.imwrite(newPath, newImg)  # 保存图片
        cv2.imshow(imgName, newImg)
        cv2.waitKey(0)
        return score 

def test():
  dp = FiveKDataProvider('2k_train')
  while True:
    d = dp.get_next_batch(64)
    cv2.imshow('img', d[0][0, :, :, ::-1])
    cv2.waitKey(0) 

def show_webcam_and_run(model, emoticons, window_size=None, window_name='webcam', update_time=10):
    """
    Shows webcam image, detects faces and its emotions in real time and draw emoticons over those faces.
    :param model: Learnt emotion detection model.
    :param emoticons: List of emotions images.
    :param window_size: Size of webcam image window.
    :param window_name: Name of webcam image window.
    :param update_time: Image update time interval.
    """
    cv2.namedWindow(window_name, WINDOW_NORMAL)
    if window_size:
        width, height = window_size
        cv2.resizeWindow(window_name, width, height)

    vc = cv2.VideoCapture(0)
    if vc.isOpened():
        read_value, webcam_image = vc.read()
    else:
        print("webcam not found")
        return

    while read_value:
        for normalized_face, (x, y, w, h) in find_faces(webcam_image):
            prediction = model.predict(normalized_face)  # do prediction
            if cv2.__version__ != '3.1.0':
                prediction = prediction[0]

            image_to_draw = emoticons[prediction]
            draw_with_alpha(webcam_image, image_to_draw, (x, y, w, h))

        cv2.imshow(window_name, webcam_image)
        read_value, webcam_image = vc.read()
        key = cv2.waitKey(update_time)

        if key == 27:  # exit on ESC
            break

    cv2.destroyWindow(window_name) 

def display(self):
        """Blit all the status on the screen"""
        self.window[: self.frame.shape[0], :, :] = self.frame
        horizon_percent = self.config["camera"]["pitch"] / self.config["camera"]["vfov"] + 0.5
        # Horizon line
        self.window[int(self.f_h * horizon_percent), :, :] = (255, 0, 255)
        # Clear status buffer
        self.window[self.f_h :, :, :] = 0
        # Draw label bar
        self.window[self.f_h : self.f_h + self.l_h // 2, :, :] = self.autonomous_bar
        self.window[self.f_h + self.l_h // 2 : self.f_h + self.l_h, :, :] = self.quality_bar
        # Draw current timestamp vertical line
        current_x = self.frame_pos(self.frame_id)
        self.window[self.f_h + self.l_h :, current_x, :] = self.bar_color(self.quality)
        # Draw zero line
        self.window[self.f_h + self.l_h + self.bhh, :, :] = (96, 96, 96)
        offset = self.f_h + self.bhh + self.l_h
        self.window[self.window_speeds + offset, np.arange(self.f_w), :] = (255, 64, 255)
        self.window[self.window_steers + offset, np.arange(self.f_w), :] = (64, 255, 255)
        text = "%05i %07.3f %06.3f %06.3f" % (self.frame_id,
                                            (self.camera_times[self.frame_id] / 1E9) % 100,
                                            self.camera_steers[self.frame_id],
                                            self.camera_speeds[self.frame_id])
        font = cv2.FONT_HERSHEY_SIMPLEX
        pink = (255, 128, 255)
        offset = (0, int(self.scale * 30))
        cv2.putText(self.window, text, offset, font, self.scale, pink, 1, cv2.LINE_AA)
        cv2.imshow(self.window_name, self.window) 

def live_calibrate(camera, pattern_shape, n_matches_needed):
    """ Find calibration parameters as the user moves a checkerboard in front of the camera """
    print("Looking for %s checkerboard" % (pattern_shape,))
    criteria = (cv2.TERM_CRITERIA_EPS + cv2.TERM_CRITERIA_MAX_ITER, 30, 0.001)
    example_3d = np.zeros((pattern_shape[0] * pattern_shape[1], 3), np.float32)
    example_3d[:, :2] = np.mgrid[0 : pattern_shape[1], 0 : pattern_shape[0]].T.reshape(-1, 2)
    points_3d = []
    points_2d = []
    while len(points_3d) < n_matches_needed:
        ret, frame = camera.cap.read()
        assert ret
        gray_frame = cv2.cvtColor(frame, cv2.COLOR_BGR2GRAY)
        ret, corners = cv2.findCirclesGrid(
            gray_frame, pattern_shape, flags=cv2.CALIB_CB_ASYMMETRIC_GRID
        )
        cv2.imshow("camera", frame)
        if ret:
            points_3d.append(example_3d.copy())
            points_2d.append(corners)
            print("Found calibration %i of %i" % (len(points_3d), n_matches_needed))
            drawn_frame = cv2.drawChessboardCorners(frame, pattern_shape, corners, ret)
            cv2.imshow("calib", drawn_frame)
        cv2.waitKey(10)
    ret, camera_matrix, distortion_coefficients, _, _ = cv2.calibrateCamera(
        points_3d, points_2d, gray_frame.shape[::-1], None, None
    )
    assert ret
    return camera_matrix, distortion_coefficients 

def test():
  dp = ArtistDataProvider('C')
  while True:
    d = dp.get_next_batch(64)
    cv2.imshow('img', d[0][0, :, :, ::-1])
    cv2.waitKey(0) 

def test1():
  import cv2
  batch_size = 1024
  img = cv2.imread('data/doggy.jpg').mean(axis=2)

  pdf_batch = np.empty(
      shape=(batch_size, img.shape[0], img.shape[1]), dtype=np.float32)

  for i in range(batch_size):
    pdf_batch[i] = img

  pdf = tf.placeholder(tf.float32, (batch_size, img.shape[0], img.shape[1]))
  noise = tf.placeholder(tf.float32, (batch_size, 1))

  with tf.Session() as sess:
    indices = pdf_sample_2d(pdf, noise)
    image_buffer = np.zeros(
        shape=(img.shape[0], img.shape[1]), dtype=np.float32)

    while True:
      indices_out = sess.run(
          indices,
          feed_dict={pdf: pdf_batch,
                     noise: np.random.rand(batch_size, 1)})

      for ind in indices_out:
        image_buffer[ind[0]][ind[1]] += 1

      cv2.imshow('img', image_buffer / np.max(image_buffer))
      cv2.waitKey(30) 

def playVideoFromAVI(s):
    cap = cv2.VideoCapture(s)
 
    # Check if camera opened successfully
    if (cap.isOpened()== False): 
      print("Error opening video stream or file")
     
    # Read until video is completed
    while(cap.isOpened()):
      # Capture frame-by-frame
      ret, frame = cap.read()
      if ret == True:
     
        # Display the resulting frame
        cv2.imshow('Frame',frame)
     
        # Press Q on keyboard to  exit
        if cv2.waitKey(1) & 0xFF == ord('q'):
          break
     
      # Break the loop
      else: 
        break
     
    # When everything done, release the video capture object
    cap.release()
     
    # Closes all the frames
    cv2.destroyAllWindows() 

def yuv_frame_cb(yuv_frame):
    """
    This function will be called by Olympe for each decoded YUV frame.

        :type yuv_frame: olympe.VideoFrame
    """
    # the VideoFrame.info() dictionary contains some useful information
    # such as the video resolution
    info = yuv_frame.info()
    height, width = info["yuv"]["height"], info["yuv"]["width"]

    # yuv_frame.vmeta() returns a dictionary that contains additional
    # metadata from the drone (GPS coordinates, battery percentage, ...)

    # convert pdraw YUV flag to OpenCV YUV flag
    cv2_cvt_color_flag = {
        PDRAW_YUV_FORMAT_I420: cv2.COLOR_YUV2BGR_I420,
        PDRAW_YUV_FORMAT_NV12: cv2.COLOR_YUV2BGR_NV12,
    }[info["yuv"]["format"]]

    # yuv_frame.as_ndarray() is a 2D numpy array with the proper "shape"
    # i.e (3 * height / 2, width) because it's a YUV I420 or NV12 frame

    # Use OpenCV to convert the yuv frame to RGB
    cv2frame = cv2.cvtColor(yuv_frame.as_ndarray(), cv2_cvt_color_flag)

    # Use OpenCV to show this frame
    cv2.imshow("Olympe Pdraw Example", cv2frame)
    cv2.waitKey(1)  # please OpenCV for 1 ms...