DLP3000: Problems calibrating DLP3000 TIDA-00361

Hi Pablo,

Sorry you're having difficulty with the camera and calibration. I am going to guess that what you are running into is that fact that the Microsoft LifeCam is an untriggered camera so you need to change some settings.

In this folder:
{installed directory}\TIDA-00361_3D_Scanner_LCr3000-2.0\LCr3000_3D_Scanner_Application_v2\config

Open:
config_projector.txt

Change:
LCR3000_PARAMETERS_INPUT_TRIGGER_TYPE from the current value (probably 0) to 1.

Let me know if that works!
Paul

Thank you for your response,

I already modified that configuration to 1. I tried doing the calibration today during the day and set the color to RED and I got better results ... my calibration is way off, but it calibrates and I get some apparently random points on the screen. It's nowhere near 0, as it should be. I'll try recalibrating eveyrthing  when it gest darker but still ... I don't think that just that is going to cut it. I'd really like some advice right now as how to procceed.

Hi Pablo,

I inferred from your first post that what was happening was that the projector wasn't shining light on the screen during the calibration procedure. It seems clear to me now that you are getting the projected light which is good.

I don't fully understand your issue, can you perhaps attach a picture of what you're seeing when you say "glare on the camera is too bright"? Have you tried playing with the camera settings to see if you can reduce the exposure?

-Paul

The thing is that this i supposed to be able to get 3d models out of the box, but it doesn't.

My setup for testing:
- I glued the calibration board to a white wall;
- Put the LightCrafter3000 on a white table by my side pointing at the wall (apparently it's reflective)

As it's getting darker the results get worse and worse. When there is daylight it is possible to see in the capture screen that the light is discernible and that there are squares in the image, but as it gets darker, the images only show a very bright projected board, and the calibration board disappears. I saw the test report and in it it was very clear to see that the capture was being done in a dark environment, so night time should not be a problem.

The guide says that the board should be well iluminated, I assume that by the projector, even if it requires more lighting, I did it, I turned on the fluorescent lights in here but still ... it doesn't even get one board for system calibration

Yes .. I have tried messing with all the parameters in the config files, I even made a small program that uses IAMCameraControl in order to use different values of exposure (now it's on its minimum value). I made a small video showing my problem. Sorry that it was a video but I asn't able to capture my exact problem with print screen ... apparently I'm too slow

Hi Pablo,

It looks to me that the Microsoft camera is still set to some sort of autoexposure mode, causing it to capture a picture when the image is too bright.

From the user's guide, I would advise that you do the following:

After the camera software has been installed, the camera should be configured so that the auto-exposure and auto-focus are both turned off:

1. Open the LifeCam software with the camera connected and a live view should open. Click the arrow on the right side of the window.

2. A new window will open to adjust effects of settings of the camera. Click the gear button at the top of the window to show the settings.

3. Uncheck the "truecolor" checkbox.

4. Click the "Properties" button.

5. From the "Camera Control" tab, uncheck the auto-focus checkbox and click "Apply."

6. Change to the "Video Settings" tab, and set the "Brightness" and "Saturation" settings to their absolute minimum values.

7. Uncheck both the auto-white balance and auto-exposure checkboxes and click "Apply."

8. With the LightCrafter projecting a white test pattern, adjust the Exposure settings until the image is well exposed but not over-exposed

Let me know if that works,

-Paul

Sorry again it took such a long time to answer. I did it, I disabled truecolor and disabled auto exposure and it started working. Now I have a camera calibration of 0.5 and a projector calibration of 1.5, but still I'm unable to get satisfactory results. Whatever I put in front of the DLP for scanning doesn't give me a good result ... Doing only the vertical scan the object sometimes appears to be there, doing only the horizontal scan at best I get the upper and lower edgs of the object, and when I do both, the best result I get is something similar to the horizontal scan, and I can't see the object being scanned in the resulting scan

Hi Pablo,

Glad that the calibration issues were resolved. Can you post a picture of your setup? Sometimes issues like you're describing can be due to the relative position of the camera and projector. There are also other concerns like making sure the camera/projector positions don't move after calibration.

-Paul

I did this, things got better, I was able to calibrate and I've been constantly capable of calibrating the entire system without problems and even getting decent results (0.3 and 1.4 was my best), but I'm still unable to get a decent scan. I have fake teeth to scan, something similar to the example given in the test report of TIDA-00361 but I'm still only able to get the outline of the fake teeth and quite a bad outline.

Any ideas what might be happening? Is itperhaps a problem with my camera?

Hi Pablo,

Sorry that you're having trouble. It would be very helpful is you could post a picture of your setup. Then I could look at and see if I notice anything. 

One thought I had is that you may need to adjust your exposure after calibration for the object that you are scanning. If you are scanning a darker object for instance, you may not be getting enough light.

Check the Output/scan_images folder to see if the images taken by the camera look like they have enough light and that they are in focus.

Best,

Paul

Hi, sorry it took me such a long time to answer.

I was finally able to get a better result. It's still not good yet, but it's better. What I did was move the dlp closer to the object being scanned ... the thing is that I had to find the correct distance because the DLP wasn't able to do a clear projection on the object. I noticed this when I was staring at the object while it was being scanned and all that I could see was a projection without stripes (the last 4 or 5 projection of each direction looked like an entirely green projection without lines), even in the pictures.

It took me a while but I found a decent distance for the camera and the projector. And it didn't work during the day .. only at night in a completely dark room.

Is there a way to improve the projection resolution?? If I was able to do a better, more clear projection at a closer distance I think I could get better results

Hi Pablo,

The best hardware way to improve the resolution is to use a higher resolution camera. You can also work on implementing your own software to accomplish your goals and use better algorithms than the ones we use.

Your comment about "clear projection" makes me wonder if the projector is properly focused. The lines should be sharp and all the patterns should be easily distinguishable by the eye. If they are too blurry, then as you noted, the last few patterns will appear to have no lines at all. Proper focusing will dramatically improve your results.

-Paul

He Paul,

The camera is ok ... it's not as good as the on being used in the example, but it's good. I can get a great resolution image, it just needs to be closer to the target than in you example.

My real problem is with the projector. It seems out of focus as you said. In the last patterns it's very difficult to see them, even in the images taken by the camera. The thing is that when I get closer to the checker board they get very blurry very fast ... just as much as when I try to take the projector to a greater distance. There appears to be a "sweet spot", but I can't determine it clearly ... it appears to change every once in a while. It would be great if I was able to get a better focus, but I was only able to get a decent (not good .. just decent) focus once and I can't seem to get the same results ever since that day. Are there any configurations I can modifyin order to get this better focus?

Hi Pablo,

Are you using the focus adjustment slider on the side of the Lightcrafter? That's how you can achieve perfect focus. The image should be quite sharp.

Best,
Paul