Common Scan Issues

Understanding the scan process and certain scan results might be tricky at first. In this article, we'll cover the common scan issues and how to resolve them.

Possible issues:

  1. Large parts of the scan are missing / too many holes in the scan
  2. Scan image contains significant distortion or noise
  3. Scan image looks pixelated or not crisp; the text is jagged or hard to read
  4. Scan image has wobbly edges
  5. Scan image is dark and has noise
  6. Movement during the scan process
  7. Scanning reflective surfaces
  8. Scanning with a projector that is out of focus
  9. Scanning very thin materials

Large parts of the scan are missing / too many holes in the scan

Most likely due to one of the following

  • The projector is not bright enough
  • Scene materials are too dark
  • Too much ambient light (sunlight, etc)

Possible solutions

  • Use the Camera Mask and select the entire projected region
  • Use the '3 Exposure" HDR setting
  • Move your projector closer to the objects and/or reduce the amount of external lighting

Scan image contains significant distortion or noise

Most likely due to one of the following

  • shiny
  • reflective
  • transparent materials in the scene

Possible solutions

  • Use the Camera Mask setting to select only parts of the scene you are interested in projecting on
  • Enable the Noise Reduction checkbox

Scan image looks pixelated or not crisp; text is jagged or hard to read

Possible solutions

    • Enable the Smoothing checkbox
    • Use the Camera Mask setting to select only parts of the scene you are interested in projecting on

Scan image has wobbly edges

Most likely due to

  • Blind spots: An important concept to understand with the Lightform device scan is "hole-filling." Because the Lightform device camera lens and your projector lens can never be in the exact same physical position, there will always be small portions of the scene that can be seen by one lens but not the other. These are referred to as "shadows" or "blind spots."
    1_csi.png
    In the above diagram, the projector is able to see underneath the shelf and plant, but the Lightform device can not. This will result in a shadow in the final scan, which is normal.

    Automatic Hole-Filling

    After a scan is complete, Lightform Creator attempts to fill in these blindspots using a 'nearest neighbor' technique. Essentially, the software samples nearby colors and attempts to fill in the shadows according to nearby values.

    However, it is often the case that you will not want hole filling at the maximum setting because this can cause an effect where your scan has "wobbly edges," making it difficult to create a precise mask.

Possible Solutions

  • Modify the Hole Filling slider in the Scan Properties after the scan is complete.

    Optimal Hole-Filling Technique

    To get precise edges in your scan by decrease the Hole Filling slider all the way to 0%, then slowly bringing it back up to an amount where your objects are fully filled in, but the shadows are not. In this particular case, around 20%.

    hole-fill-100.jpg

    Trying to create a precise mask with 100% Hole Filling, it can sometimes be difficult to determine where the edge of an object is.

    hole-fill-19.jpg

    With Hole Filling set to 19%, we are able to see clearly where the Lightform device's blind spots are, and therefore create a nice clean mask on the flower.

Scan image is dark and has noise

projector-color.jpgProjector Scan Result that appears dark and noisy

Most likely due to

  • Dark environment: When scanning in dark environments, the projector scan result looks dark and noisy.

Possible Solutions

  • Adjust the Brightness slider. After your scan is complete and before you add any surfaces, adjust the Brightness slider in the Scan Properties to blend between the "projector off" and "projector on" scan images.

    When the Lightform device performs a scan, it produces two final images: one with the projector 100% off, and one with the projector 100% white. In dark environments, the "projector off" image may be under-exposed and appear noisy. You can blend between these images by adjusting the brightness slider.

    ezgif-4-3b1ff07c1213.gifprojector-color1.jpg

Projector Scan Result that appears bright and clean


Movement during the scan process

projector-color-1.jpgProjector Scan Result

camera-color.jpgLightform Device Camera View

Most likely due to

  • Sean wanted to show off his cool tropical shirt while we were doing a scan. This caused incorrect gray code correspondences and affected other regions of the scan. Thanks, Sean. 🙄

Possible solutions

  • Get Sean outta there! It is important to have no movement in the projection area while performing a scan.

Scanning reflective surfaces

projector-color-2.jpgProjector Scan Result

camera-color-1.jpgLightform Device Camera View

Most likely due to

  • This scene includes many reflective and transparent materials, which can cause the light of the Lightform device's gray codes to bounce around and create incorrect correspondences.

Possible solutions

  • Reduce or remove all reflective and transparent surfaces, or rotate them so the light is not being bounced into other areas of the scene.
  • You can treat reflective surfaces with a temporary dulling spray. This will give them a more matte finish which will scan better.

    Here are our recommended dulling sprays:
    1. Krylon Matte Dulling Spray (North America)
      https://www.krylon.com/products/dulling-spray/
    2. K-Line Matt Dulling Spray (Europe)
      https://www.swkenyon.com/matt-dulling-spray.php

Scanning with a projector that is out of focus

Capture.pngLive Camera Preview (before scan)

projector-color-3.jpgProjector Scan Result

Most likely due to

  • If the projector is out of focus the scan result will be noisy and with a lot of holes.

Possible solution

  • When you see the Lightform device's test pattern before you perform a scan, ensure that the projector is in focus, and you see sharp pixels on the object you are trying to scan.

Scanning very thin materials

projector-color-4.jpgProjector Scan Result

camera-color-2.jpgLightform Device Camera View

Most likely due to

  • very thin materials such as string can come out looking wobbly, or not show up at all in a scan.

Possible solutions

  • If you can see the material in the scan but it looks wobbly, refer to the above solution for Scan image has wobbly edges
  • If the material is so thin it does not appear at all, then you can try moving the projector closer, or avoid using this material entirely.
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  • Comment actions Permalink
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    Molly Toberer

    Please expand on scanning technical difficulties. I cant get any good scans only giant uneven holes.

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    Ashley Russell

    Hi Molly, 

    We're sorry for the trouble you've been experiencing with scanning. The first thing I'd check is to make sure you can see the test card pattern displayed over your scene very visibly before taking your scan. If the ambient light in the room is too bright and you can't see the test pattern clearly, this might be an issue.

    So we can assess the issue and provide more detailed recommendations, would you mind sending us a recent project with bad scans that you've saved? To do so, please go to File->Archive Project, create a new directory in a common location to save the project to and then zip up the saved archive directory and send it to us at support@lightform.com

    Thanks,

    Ashley

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    Rick Robinson

    I have the LFC and projector covering my entire house with a few feet extra on each side to the left and right. I have tried scans at several times of the evening which included complete darkness to around dusk.


    All of the scans are about the same, there are large holes on the left and right-hand side. I would say about 85% of the house is perfect but the outside edges are not.

    Any suggestions on how to have a good scan cover the entire house? If not, is it possible to combine scans to make one good one?

    Thanks,

     

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    Anum

    Hi Rick Robinson, have you tried using the Camera Mask feature in the scan dialog? It gives you the option to define a region to scan by drawing a rectangle around it and can prevent holes from appearing in scans. Give it a try and if you're still having issues please reach out to us at support@lightform.com