Can't run Camera Alignment Wizard (Linux: Ubuntu 18.04)


(Clinton Paris) #1

Using Lightburn under Linux (Ubuntu 1804):

Ok, so Camera Lens Calibration went great! I then moved in to Camera Alignment and that’s when things broke down. Looking at the Debug Log:

QMetaObject::connectSlotsByName: No matching signal for on_image_doubleClicked(QPointF&)
isFisheye: false
reading camera matrix
2508.5
0
0
0
2517.28
0
1623.54
1217.95
1
reading lens distortion matrix
-0.0290124
0.0387347
-0.000149726
0.00170397
-0.0496154

(AppRun:22874): GStreamer-CRITICAL **: 21:16:43.336: gst_element_link_pads_full: assertion 'GST_IS_ELEMENT (src)' failed

(AppRun:22874): GStreamer-CRITICAL **: 21:16:43.336: gst_object_unref: assertion 'object != NULL' failed
Setting res: 3264  x  2448
CameraBin error: "GStreamer error: negotiation problem."
CameraBin error: "Internal data stream error."
CameraBin error: "Internal data stream error."

So LB is able to interact with the camera enough to do the lens calibration, so it feels more like a LB error than a gstreamer error.

Edit: Seems to be the same problem as given in Camera calibration in Linux thread.

Thanks in advance for any assistance you can lend! :slight_smile:


(Stephen Schlie) #2

I’m seeing the same issue, the lens calibration went very well, I can see the image in the “camera control” panel as well (verified it is a live feed) but when I try to run the alignment too I’m seeing errors. Here is the log from start up to opening the camera control panel, and then opening the alignment tool:

libpng warning: iCCP: known incorrect sRGB profile
Port open succeeded
Port open succeeded
res: 640  x  480
res: 800  x  600
res: 1024  x  768
res: 1280  x  720
res: 1280  x  1024
res: 1600  x  1200
res: 1920  x  1080
res: 2048  x  1536
res: 2592  x  1944
default: -1  x  -1
Setting res: 2592  x  1944
QMetaObject::connectSlotsByName: No matching signal for on_image_doubleClicked(QPointF&)
isFisheye: false
reading camera matrix
1455.54
0
0
0
1456.98
0
1305.85
1000.71
1
reading lens distortion matrix
0.0285287
-0.00921406
0.00304194
-0.0102641
-0.00144401

(LightBurn:12424): GStreamer-CRITICAL **: 15:21:15.287: gst_element_link_pads_full: assertion 'GST_IS_ELEMENT (src)' failed

(LightBurn:12424): GStreamer-CRITICAL **: 15:21:15.287: gst_object_unref: assertion 'object != NULL' failed
Setting res: 2592  x  1944
CameraBin error: "GStreamer error: negotiation problem."
CameraBin error: "Internal data stream error."
CameraBin error: "Internal data stream error."

(Clinton Paris) #3

As a non-elegant workaround:

So I’m think of aligning the camera in Windows, then rebooting back to Linux, then copying the saved alignment data from the Windows partition for use by the Linux version. It seems logical that it would work.

Should be a fun experiment! :slight_smile:


(Clinton Paris) #4

The experiment didn’t quite work:

I rebooted into Windows, then ran the Lens Calibration followed by the Camera Alignment. I then exited out and made a copy of the prefs.ini file.

After rebooting back to Linux, I modified the existing prefs.ini (located in .config) with the values from the Windows version. When trying to Update Overlay, the image shown in the work area is highly distorted. This was kind of confusing, since I assumed that the Windows and Linux versions of the software would use the same config file settings.

I then ran the Lens Calibration under Linux, then exited out. Upon looking at the pref.ini files and comparing the cameraMatrix and distortionMatrix values, the Windows and Linux versions were REALLY different.

Linux Values:

"cameraMatrix": [
                    2296.7865652045816,
                    0,
                    0,
                    0,
                    2317.8591320596565,
                    0,
                    1565.037367819448,
                    1117.9728734289406,
                    1
                ],
                "distortionMatrix": [
                    -1.02011437709958077,
                    -0.008554693137637471,
                    0.0011069906616131085,
                    -0.001360108203982642,
                    0.029314921473487947
                ],

Windows Values:

"cameraMatrix": [
                    1259.3393049091812,
                    0,
                    0,
                    0,
                    1264.1082471008497,
                    0,
                    778.6335514058632,
                    618.1813070596527,
                    1
                ],
                "distortionMatrix": [
                    -0.019285227387470388,
                    -0.0014769580907604512,
                    0.0022174800358205956,
                    8.704968569868195e-06,
                    0.030781767551214353
                ],

It was worth a shot! Hopefully this little camera bug can get snuffed out for the next build of LB. The camera integration seems like the killer feature–can’t wait to really use it! :slight_smile:


(Stephen Schlie) #5

Heya, as I can’t find a bug tracker anywhere I wanted to see if there is a way to make sure this is on the creators radar. I saw in the linked post a comment about not yet having a dedicated Linux machine to test on but that was going to be resolved soon. I am on the verge or purchasing this, and while it isn’t a deal breaker to not have the feature it is very nice to have.


(Clinton Paris) #6

Agreed. The two reasons I purchased Lightburn are the camera support, and the fact that they support Linux.