Aborting a capture command waiting for a trigger

[benthie (Benjamin Thiemann)]

Hi there,

@techno

If the stereo camera times out and then receives a stereo image while waiting for a color image for 5 seconds, will the Retrieve command result in ”CaptureTimeOut Exception”?

Yes, it will return with the error symbol errCaptureTimeout.

@techno

Also, what will happen to the asBool() for each camera?

When searching for “Retrieve finalize” in the log file, we can see that there is a block for each Retrieve command that is executed. You search the one belonging to your current command by hovering over it in the search list at the bottom, which highlights the block in the timeline.

The one you search contains a message “Command result as JSON”, which is as follows:

Command result as JSON:
{
	"244888": {
		"Images": null,
		"Retrieved": false
	},
	"244888-Color": {
		"Exposure": 30.584,
		"Gain": 2.533,
		"Images": 13386747925.028,
		"PacketsResent": 0,
		"Retrieved": true
	},
	"ErrorSymbol": "CaptureTimeout",
	"ErrorText": "Waiting for images timed out.",
	"Execute": {
		"Command": "Retrieve",
		"Parameters": {
			"Cameras": null,
			"OpenMP": {
				"Dynamic": 1
			},
			"Threads": 10,
			"Timeout": 5000
		}
	}
}

Here we can see, that a timeout occurred for the stereo camera, while the image for the color camera has been retrieved.

---

About the last log file you provided: Can you open the file under Windows? Because I can’t under Linux, which seems to be a bug on our side. But it would be interesting to know, if this only happens on Linux.

Kind Regards
Benny

[techno]

@benthie

Here we can see, that a timeout occurred for the stereo camera, while the image for the color camera has been retrieved.

In that case, is it correct to understand that if I
“run retrieve again if asBool() becomes true for only one of the cameras”,
I will be able to obtain images from both?

---

Sorry. As you said, when I opened the uploaded file, nxprofiler closed.
The LOG I got again is below.
(I confirmed that the LOG can be opened normally.)
tmp_NxTreeEdit20250320-release.zip (30.8 MB)

Thanks for your support and
With kind regards
K.N.

[benthie (Benjamin Thiemann)]

Hi there,

@techno

To measure the time difference(or a value close to it) between the start of exposure on the Stereo Camera and the Color Camera from the LOG, what interval should I measure?

@techno

What I wanted to know was the timing difference between the stereo image and the color image when the trigger was turned on in the latest state where the retrieve was set to wait infinitely.

I am still not quite sure if I understand your question. But let me try to answer from what I understand: You would like to know the time between the start of the exposure on the stereo camera and the start of the exposure of the color camera. The NxLib unfortunately does not know when the stereo camera receives its hardware trigger, so the information on when the stereo exposure starts is not available in the logs.

You can, however, have a look at the timestamps and the result node of a successful Retrieve command. The following is the result as JSON from a successful retrieval (Aft20min-Trig2timesCapture2times). Our raw image node documentation states, that the timestamps represent the actual trigger time/exposure start. With the information you could calculate the time difference.

Command result as JSON:
{
	"244888": {
		"Exposure": 2.89,
		"Gain": 1,
		"Images": {
			"Raw": [
				{
					"Left": 13386768768.221,
					"Right": 13386768768.268
				},
				{
					"Left": 13386768768.352,
					"Right": 13386768768.311
				},
				{
					"Left": 13386768768.394,
					"Right": 13386768768.434
				}
			]
		},
		"PacketsResent": 0,
		"ProjectorWaitingTime": 0,
		"Retrieved": true
	},
	"244888-Color": {
		"Exposure": 30.584,
		"Gain": 2.533,
		"Images": 13386768768.477,
		"PacketsResent": 0,
		"Retrieved": true
	}
}

Kind Regards
Benny

[techno]

Hi Benjamin

Thank you for your reply.
I was satisfied with what you said,
which was what I wanted to hear.

From what I received,
I understand that the time difference between
the left image and the color image captured with the first FlexView is
256[ms] = 0.256 ≈ 13386768768.477 - 13386768768.221.

If my understanding is incorrect, please point it out.

Thanks for your support and
With kind regards
K.N.