Use multiple ZED camera with the python Package

[ralf307]

Hello,

thanks a lot for your sharing! However, here I still have a quetion when using this python package (not cpp):

when my computer is connected with multiple ZED camera (e.g., two), then how can I access them separately using some identifier as parameter in your code? I just want to use those two ZED cams to take pictures in different directions.

Best regards, XG

[ultrafro]

Thanks for sharing! This is a great extension of the SDK. I think the multiple ZED is an important feature and it would be great to see it in the python SDK. Is there any plan to include this? If not, any tips how we can extend it?

Thanks!

[adujardin]

Hi, This is already implemented, you have to set the camera ID PyInitParameters.camera_linux_id

Here is a simple example with 2 ZED: https://gist.github.com/adujardin/14843cb6f6f1380ad5ca9b948f85c531

[nalinraut]

` import cv2 import pyzed.sl as sl zed1 = sl.Camera() zed2 = sl.Camera()

def main(): print("Running...") init_params = sl.InitParameters() init_params.camera_resolution = sl.RESOLUTION.RESOLUTION_HD720 init_params.camera_fps = 30

init_params.camera_linux_id = 0
if not zed1.is_opened():
    print("Opening ZED Camera 1 ...")

err = zed1.open(init_params)
if err != sl.ERROR_CODE.SUCCESS:
    print(repr(err))
    exit(1)

init_params.camera_linux_id = 1 # Specify the camera index
if not zed2.is_opened():
    print("Opening ZED Camera 2 ...")

err = zed2.open(init_params)
if err != sl.ERROR_CODE.SUCCESS:
    print(repr(err))
    exit(1)

runtime = sl.RuntimeParameters()
mat1 = sl.Mat()
mat2 = sl.Mat()

print_camera_information(zed1)
print_camera_information(zed2)

key = ''
while key != 113:  # for 'q' key
    err = zed1.grab(runtime)
    if err == sl.ERROR_CODE.SUCCESS:
        zed1.retrieve_image(mat1, sl.VIEW.VIEW_LEFT)
        cv2.imshow("ZED 1", mat1.get_data())

    err = zed2.grab(runtime)
    if err == sl.ERROR_CODE.SUCCESS:
        zed2.retrieve_image(mat2, sl.VIEW.VIEW_LEFT)
        cv2.imshow("ZED 2", mat2.get_data())

    key = cv2.waitKey(5)
cv2.destroyAllWindows()

zed1.close()
zed2.close()
print("\nFINISH")

def print_camera_information(cam): print("Resolution: {0}, {1}.".format( round(cam.get_resolution().width, 2), cam.get_resolution().height)) print("Camera FPS: {0}.".format(cam.get_camera_fps())) print("Firmware: {0}.".format( cam.get_camera_information().firmware_version)) print("Serial number: {0}.\n".format( cam.get_camera_information().serial_number))

if name == "main": main() `

[mminervini]

Hi,

I am trying to select a camera in a multi-camera setting based on the serial number, using the set_from_serial_number() function from InitParameters.input, however, when I open() with those init_params, the serial number appears to be ignored and another camera is opened. Even if I use a random non-existent serial number, upon opening no error is issued and the same default camera is accessed.

Is set_from_serial_number() reliable or camera_linux_id is the only viable option to select a camera? (I'm in a Linux environment.)

Thanks in advance!

Best, Massimo

[abastie]

Hi @mminervini ,

To fix your problem you can use the function set_from_serial_number() from InitParameters so use :

init.set_from_serial_number(num)

instead of :

init.input.set_from_serial_number(num)

You can also create an object InputType use the function and then assign it to the InitParameters but this is more laborious. We will soon remove this ambiguity to avoid confusion so you can just use the set_from functions directly for InitParameters.

Thanks for your report.