The camera frequency is set, but the time stamp when capturing the picture is incorrect

[P970727]

Preliminary Checks

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Description

Timestamp interval is not 1 / 30s，Inconsistent timestamp interval.

Steps to Reproduce

from os import TMP_MAX from time import monotonic import pyzed.sl as sl import cv2 import pandas as pd import numpy as np

zed = sl.Camera()

Set configuration parameters

init_params = sl.InitParameters() init_params.camera_resolution = sl.RESOLUTION.HD1080 init_params.camera_fps = 30 #相机的频率 #init_params.coordinate_units = sl.UNIT.METERS #坐标系单位 #init_params.depth_minimum_distance = 0.15 #Set the minimum depth perception distance to 15cm #init_params.depth_maximum_distance = 20 #25m init_params.depth_mode = sl.DEPTH_MODE.ULTRA #init_params.sdk_gpu_id = 1#gpu

#Ultra模式提供最高的深度范围，并在感应范围内更好地保留Z精度

sp = sl.SensorParameters() sp.sampling_rate = 0.9 #采样率 moi = sp.noise_density #白噪音 mwork = sp.random_walk #随机游走 print(moi) print(mwork)

#是否开启成功 err = zed.open(init_params) if err != sl.ERROR_CODE.SUCCESS: print("没启动成功！") exit(-1)

传感器

sensors_data = sl.SensorsData()

#捕获图片 #image = sl.Mat() left_image = sl.Mat() depth_image = sl.Mat()

#imu表格格式 #右手系，后z，上y，左下。而EuRoc则是后-z，上x，左y。表格格式以EuRoc为主 name=['##timestamp [ms]','w_RS_S_x [rad s^-1]','w_RS_S_y [rad s^-1]','w_RS_S_z [rad s^-1]', 'a_RS_S_x [m s^-2]','a_RS_S_y [m s^-2]','a_RS_S_z [m s^-2]'] csv=[]

key='' i=0 print("按q----退出") while i<200 :#按了q也不管用啊 key != 113

if zed.grab() == sl.ERROR_CODE.SUCCESS:
# A new image is available if grab() returns SUCCESS
    #获取图片（彩色图、深度图）
    zed.retrieve_image(left_image, sl.VIEW.LEFT) # Retrieve the left image
    zed.retrieve_image(depth_image, sl.VIEW.DEPTH) # Get a grayscale preview of the depth map

    #提取imu数据
    zed.get_sensors_data(sensors_data, sl.TIME_REFERENCE.IMAGE) # Retrieve only frame synchronized data
    imu_data = sensors_data.get_imu_data()
    
    #获得时间戳
    timestamp = zed.get_timestamp(sl.TIME_REFERENCE.IMAGE) 
    #print("Image resolution: ", image.get_width(), " x ", image.get_height()," || Image timestamp: ", timestamp.get_milliseconds())
    
    #存图片
    #j = str(i) +'zed'

    img_left = left_image.get_data() 
    img_depth = depth_image.get_data() 

    # img = np.hstack([img_left, img_depth])
    # img = cv2.resize(img, (800, 400))
    # cv2.imshow("ZED-depth", img)
    #cv2.imwrite("./picture/"+j+'.png',img)
    cv2.imwrite('./picture/image/{:06}.png'.format(i),img_left)
    cv2.imwrite('./picture/depth/{:06}.png'.format(i),img_depth)
    

    #获得imu的角速度、加速度，并存入csv列表中
    # Retrieve linear acceleration and angular velocity
    angular_velocity = imu_data.get_angular_velocity()#3x1 角速度
    # tmp = angular_velocity[0]
    # angular_velocity[0] = angular_velocity[1]
    # angular_velocity[1] = tmp
    # angular_velocity[2] = 0-angular_velocity[2]
    
    linear_acceleration = imu_data.get_linear_acceleration()#3x1  线加速度
    # tmp = linear_acceleration[0]
    # linear_acceleration[0] = linear_acceleration[1]
    # linear_acceleration[1] = tmp
    # linear_acceleration[2] = 0-linear_acceleration[2]

    res = []
    res.append(timestamp.get_milliseconds())#毫秒
    res.extend(angular_velocity)
    res.extend(linear_acceleration)
    csv.append(res)
   
   
    key = cv2.waitKey(5)
    print(key)
    
#更新帧数
i=i+1

df = pd.DataFrame(columns=name, data=csv) df.to_csv('./picture/imu.csv', index=False)#保存imu表格数据 cv2.destroyAllWindows() zed.close()

Expected Result

The interval between timestamps is fixed at 1 / 30s

Actual Result

Timestamp interval is not 1 / 30s，Inconsistent timestamp interval.

ZED Camera model

ZED2

Environment

ubuntu18.04
zed sdk 3.7.2

Anything else?

No response

[github-actions[bot]]

This issue is stale because it has been open 30 days with no activity. Remove stale label or comment otherwise it will be automatically closed in 5 days

[fennecinspace]

I'm trying to sync multiple SVO files a remove excess frames from start and end, to have same length synced recordings from multiple ZED cameras. and this issue is stopping me from doing that.

[github-actions[bot]]

This issue is stale because it has been open 30 days with no activity. Remove stale label or comment otherwise it will be automatically closed in 5 days

[fennecinspace]

Exists still.

[github-actions[bot]]

This issue is stale because it has been open 30 days with no activity. Remove stale label or comment otherwise it will be automatically closed in 5 days