Will ZED Explorer recalibrate without CUDA?

[AdrianaGVL]

I’ve been recording with the ZED Explorer app on my laptop which has no GPU.
I would like to know if the ZED Explorer app will still recalibrate the camera even if CUDA is not available.

And just one last question. When computing the depth values from a SVO file, does the SDK use the calibration parameters from the config file in the settings folder, or which parameters does it use?

Thanks in advance.

[Myzhar]

Hi @AdrianaGVL
Welcome to the Stereolabs community.

@AdrianaGVL

I would like to know if the ZED Explorer app will still recalibrate the camera even if CUDA is not available.

No. ZED Explorer only acquires and displays the raw camera stream. It does not process the images and it does not rectify them before displaying.
The recorded SVO files contain the raw camera streams.

@AdrianaGVL

And just one last question. When computing the depth values from an SVO file, does the SDK use the calibration parameters from the config file in the settings folder, or which parameters does it use?

When you open an SVO from a computer different from the one used to record it, the ZED SDK automatically downloads the factory calibration file of that camera from our servers.

[AdrianaGVL]

@Myzhar

No. ZED Explorer only acquires and displays the raw camera stream. It does not process the images and it does not rectify them before displaying.
The recorded SVO files contain the raw camera streams.

Perfect, thanks

@Myzhar

When you open an SVO from a computer different from the one used to record it, the ZED SDK automatically downloads the factory calibration file of that camera from our servers.

So why is it that when I process the SVO file to extract the left frames and depth maps, the calibration parameters are not the same as those in the config file?

[Myzhar]

@AdrianaGVL

So why is it that when I process the SVO file to extract the left frames and depth maps, the calibration parameters are not the same as those in the config file?

Are your retrieving the “RAW” or the “Rectified” parameters?
Please also note that the ZED SDK has a “recalibration” feature that performs a quick calibration when opening the camera to fix little distortions introduced by shocks and temperature changing.
You can disable it if you need:
InitParameters::camera_disable_self_calib

[AdrianaGVL]

@Myzhar

Are your retrieving the “RAW” or the “Rectified” parameters?
Please also note that the ZED SDK has a “recalibration” feature that performs a quick calibration when opening the camera to fix little distortions introduced by shocks and temperature changing.
You can disable it if you need:
InitParameters::camera_disable_self_calib

Thank you for your response.

What I’m doing is this:

init_params = sl.InitParameters()
init_params.set_from_svo_file(svo_path)

But it returns different calibration parameters than those in the config file when I do not get the raw parameters. So I’m quite confused about which parameters the ZED SDK uses.
I need the calibration parameters that the ZED SDK uses because I’m trying to generate the depth maps with SfM and compare the depths.

[Myzhar]

The “not RAW” parameters are the camera settings for the rectified images, if you notice the distortion parameters are indeed null.

If you use the rectified images to generate your depth map, then you need the rectified camera parameters.

Instead, if you also perform the rectification process, you should retrieve the RAW parameters.
Read more here.

[AdrianaGVL]

Perfect. Everything is clear now.
Thank you so much!