Strange calibration and reconstruction results

[yujiazhang777]

Hi,

I always got incorrect calibration result. The camera calibration is good but the projector calibration result is totally incorrect, as well as the stereo calibration. The reprojection error of projector or stereo is more than e+02. The point cloud result is just a plane without depth information. I have tried to load the correct calibration file, but the 3D result is messed up. I also tried the matlab code and made my gamma response linear. Do you know how to resolve this problem?

Bests, Yujia

[benrennison]

Yujia, Did this ever get resolved?

[nikkadim]

@benrennison what's in particular? Have no problem with calibration. Did you play with gamma for your graphics card?

[yujiazhang777]

@benrennison Still not resolved. @nikkadim I have problem in projector calibration, the reprojection error is large. The camera calibration does not have problem. So I think the problem is in the decoding process. I loaded the correct calibration file in slstudio but the point cloud still incorrect, even using the conventional gray codec. The gamma response is not very linear but I tried to change the gamma of my graphics card and the response is much more linear (the figure shows my gamma response ). But it still not work.

[jakobwilm]

You need to get the response linear. Otherwise there is just simply no way it will ever work.

/Jakob

On 23 Jan 2018, at 18:22, yujiazhang777 notifications@github.com<mailto:notifications@github.com> wrote:

@benrennisonhttps://github.com/benrennison Still not resolved. @nikkadimhttps://github.com/nikkadim I have problem in projector calibration, the reprojection error is large. The camera calibration does not have problem. So I think the problem is in the decoding process. I loaded the correct calibration file in slstudio but the point cloud still incorrect, even using the conventional gray codec. The gamma response is not very linear but I tried to change the gamma of my graphics card and the response is much more linear (the figure shows my gamma response [epson-response-0 9]https://user-images.githubusercontent.com/32459738/35290342-f690a174-0037-11e8-8ed8-b06fe2053fb5.jpg ). But it still not work.

— You are receiving this because you are subscribed to this thread. Reply to this email directly, view it on GitHubhttps://github.com/jakobwilm/slstudio/issues/21#issuecomment-359865334, or mute the threadhttps://github.com/notifications/unsubscribe-auth/AEQSmHvoyMuKdwvUMN3psqfWpkj464Doks5tNhVqgaJpZM4RHnS4.

[Cynthia7]

Hi Jakob,

I have made the gamma response linear like the figure shows. But I still have errors in calibration and the projector and stereo calibration are totally incorrect as shown below: Camera Calibration:

• cam_error: 0.6385
• Kc: [1834.4885, 0, 1279.5; 0, 1834.4885, 959.5; 0, 0, 1]
• kc: [-0.09699, 0, 0, 0, 0] Projector Calibration:
• proj_error: 4.936
• Kp: [9959.1504, 0, 1066.7208; 0, 9959.1504, 275.43365; 0, 0, 1]
• kp: [-4.126, 0, 0, 0, 0] Stereo Calibration:
• stereo_error: 10.98
• Rp: [0.99225891, -0.015919777, 0.12316168; -0.099331938, 0.49348894, 0.86406124; -0.074534588, -0.86960638, 0.48808745]
• Tp: [-70.22, -1080, 4685] Seq error 1 cam:0.4911 proj:1.997 Seq error 2 cam:0.359 proj:3.491 Seq error 3 cam:0.6174 proj:7.768 Seq error 4 cam:0.4521 proj:4.641 Seq error 5 cam:0.751 proj:3.172 Seq error 6 cam:0.328 proj:3.354 Seq error 7 cam:0.6916 proj:3.831 My captured image is like this: Is this because that my camera image is too dark since the gamma response shows that I can only capture intensity about 120 when the projected intensity value is 255?

[jakobwilm]

Hi Cynthia,

Your data looks alright. But you should make sure that tje algorithm does not use (very noisy) data from the black checket fields. Try to write the occlusion mask to disk and/or print a grey on white checkerboard.

/Jakob

On 5 Mar 2018, at 17:42, Cynthia7 notifications@github.com<mailto:notifications@github.com> wrote:

Hi Jakob,

I have made the gamma response linear like the figure shows. [gamma_2 1_dark_03042018]https://user-images.githubusercontent.com/3238223/36986891-0148a75a-2069-11e8-9d34-bc40a5b7f32a.jpg But I still have errors in calibration and the projector and stereo calibration are totally incorrect as shown below: Camera Calibration:

• cam_error: 0.6385
• Kc: [1834.4885, 0, 1279.5; 0, 1834.4885, 959.5; 0, 0, 1]
• kc: [-0.09699, 0, 0, 0, 0] Projector Calibration:
• proj_error: 4.936
• Kp: [9959.1504, 0, 1066.7208; 0, 9959.1504, 275.43365; 0, 0, 1]
• kp: [-4.126, 0, 0, 0, 0] Stereo Calibration:
• stereo_error: 10.98
• Rp: [0.99225891, -0.015919777, 0.12316168; -0.099331938, 0.49348894, 0.86406124; -0.074534588, -0.86960638, 0.48808745]
• Tp: [-70.22, -1080, 4685] Seq error 1 cam:0.4911 proj:1.997 Seq error 2 cam:0.359 proj:3.491 Seq error 3 cam:0.6174 proj:7.768 Seq error 4 cam:0.4521 proj:4.641 Seq error 5 cam:0.751 proj:3.172 Seq error 6 cam:0.328 proj:3.354 Seq error 7 cam:0.6916 proj:3.831 My captured image is like this: [frameseq_02]https://user-images.githubusercontent.com/3238223/36987323-0d242198-206a-11e8-8682-87f5934fe5a8.jpg Is this because that my camera image is too dark since the gamma response shows that I can only capture intensity about 120 when the projected intensity value is 255?

— You are receiving this because you modified the open/close state. Reply to this email directly, view it on GitHubhttps://github.com/jakobwilm/slstudio/issues/21#issuecomment-370481707, or mute the threadhttps://github.com/notifications/unsubscribe-auth/AEQSmLxdNzOJFZhYSGp-uPmkfPmUt5qSks5tbWrcgaJpZM4RHnS4.

[Cynthia7]

OK, I will try that. Thank you for your suggestion.

Bests, Yujia Zhang

2018-03-05 11:50 GMT-05:00 Jakob Wilm notifications@github.com:

Hi Cynthia,

Your data looks alright. But you should make sure that tje algorithm does not use (very noisy) data from the black checket fields. Try to write the occlusion mask to disk and/or print a grey on white checkerboard.

/Jakob

On 5 Mar 2018, at 17:42, Cynthia7 <notifications@github.com<mailto: notifications@github.com>> wrote:

Hi Jakob,

I have made the gamma response linear like the figure shows. [gamma_2 1_dark_03042018]https://user-images.githubusercontent.com/ 3238223/36986891-0148a75a-2069-11e8-9d34-bc40a5b7f32a.jpg But I still have errors in calibration and the projector and stereo calibration are totally incorrect as shown below: Camera Calibration:

• cam_error: 0.6385
• Kc: [1834.4885, 0, 1279.5; 0, 1834.4885, 959.5; 0, 0, 1]
• kc: [-0.09699, 0, 0, 0, 0] Projector Calibration:
• proj_error: 4.936
• Kp: [9959.1504, 0, 1066.7208; 0, 9959.1504, 275.43365; 0, 0, 1]
• kp: [-4.126, 0, 0, 0, 0] Stereo Calibration:
• stereo_error: 10.98
• Rp: [0.99225891, -0.015919777, 0.12316168; -0.099331938, 0.49348894, 0.86406124; -0.074534588, -0.86960638, 0.48808745]
• Tp: [-70.22, -1080, 4685] Seq error 1 cam:0.4911 proj:1.997 Seq error 2 cam:0.359 proj:3.491 Seq error 3 cam:0.6174 proj:7.768 Seq error 4 cam:0.4521 proj:4.641 Seq error 5 cam:0.751 proj:3.172 Seq error 6 cam:0.328 proj:3.354 Seq error 7 cam:0.6916 proj:3.831 My captured image is like this: [frameseq_02]https://user-images.githubusercontent.com/ 3238223/36987323-0d242198-206a-11e8-8682-87f5934fe5a8.jpg Is this because that my camera image is too dark since the gamma response shows that I can only capture intensity about 120 when the projected intensity value is 255?

— You are receiving this because you modified the open/close state. Reply to this email directly, view it on GitHubhttps://github.com/ jakobwilm/slstudio/issues/21#issuecomment-370481707, or mute the thread< https://github.com/notifications/unsubscribe-auth/AEQSmLxdNzOJFZhYSGp- uPmkfPmUt5qSks5tbWrcgaJpZM4RHnS4>.

— You are receiving this because you commented. Reply to this email directly, view it on GitHub https://github.com/jakobwilm/slstudio/issues/21#issuecomment-370484274, or mute the thread https://github.com/notifications/unsubscribe-auth/ADFpT2CSAWELQMUWNQwTOynqS45rc9Qeks5tbWyjgaJpZM4RHnS4 .