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  • Image rejection during reconstruction

    Can anyone advice this (ancient) novice? I can't get beyond the camera orientation stage in the wokflow. No matter how many photos I input only a few get acepted for reconstruction. For example 7 of 50; 5 of 34; 3 of 14. Always the first few in a circular set and all very close in overlap within a small arc. Image Quality Index value are from 4.1 to 2.5. The photos are all around 1.5mb. I've tried both a Panasonic Lumix and a 6th generation IPad, still shots and videos, but the same situation occurs. The 'Deep' setting, as advised in the tutorial video if images are rejected, only gains 1 or 2 more.
    I note that the images in the 'Cherub' test dataset are all 7 to 8mb.

  • #2
    Hi bratpat welcome to the forum!

    Can you please upload the images you are trying to process with Zephyr (using a service like Google Drive or WeTransfer) and share a download link with us? With those images we will be able to give you some targeted feedback. If you want to share the download link in private you can send it to support@3dflow.net and I will pick it up from there.

    You may have already seen but here are all of our video tutorials and written documentation for Zephyr: https://www.3dflow.net/technology/do...hyr-tutorials/

    Sometimes the issue is the camera settings, sometimes it's the subject itself, and occasionally it's something weird which requires a deeper drive, but once we have had a look at your images I'm sure we will determine the issue and get you on track to making great reconstructions!

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    • #3
      hI cam3d, thanks for such a prompt response.

      I have aleady viewed the tutorials and have printed out the full mamual for reference, but thanks anyway. The black background on the screen grabs is very poor for viewing though.

      I will put the images into Dropbox and send a link as requested.

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      • #4
        Hi again cam3d

        Dropbox link sent, plus the file folder (Pilot 1) added on Google Drive in case you don't have a Dropbox account.

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        • #5
          Hi bratpat thanks for sending through those images. Here's my feedback:

          - Don't post process your images (cropping etc..) I see that there are different size images in the set you provided - Ideally keep your images as close to 'in camera' as possible.
          - More light! You either need to go outside on a bright and cloudy day, or use studio lights inside. This is a major factor in image quality.
          - Use a turntable (and masking) https://www.3dflow.net/technology/do...for-turntable/
          - Take more photographs
          - Use the dedicated camera rather than the iPad.
          - Practice makes perfect - Your output reconstruction will only ever be as good as the photos you use to create it, so get familiar with using your camera in manual mode to your advantage :-)

          I hope some of these tips help -

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          • #6
            Hi again cam3d

            Great! used the Lumix camera; waited for the sun to go in and took the shots outside; did not crop the reults - and all 26 images loaded OK and Zephyr cameras were set. However, the model when generated (with masking selected) has all of the white paper (uncropped) on which it was standing as part of it. How do I get rid of that. I can't see anything that will do it in the tutorials or the various menu items. I loaded the file into VoxelMaker to get a file for printing anyway but it showed the massive paper base, with jagged edges.

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            • #7
              Have patience with this old guy cam3d. I've realised that masking by Masqureade needs to be done on the images before starting the workflow. No wonder it wasn't helping. My excuse is that the dark videos are very difficult to follow and certain features seem slightly different on the curent version - no 'Close Range' for instance so I used 'General'. I'll concentrate hard but if you have any tips in the meantime they would be much appreciatedon.

              Thanks again

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              • #8
                Hi again cam3d

                Oh dear, I thought I was getting somewhere. I masked all 26 images in Masquerade using the red and blue brushes on each image in turn. When I then ran the workflow again only 13 masked images were accepted. Why would masking make things worse? I doubt that number of images will make the model OK for printing, but in any case I can't see how to export it as an object. The Export menu only gives a mesh or a pdf option. Save only gives me a.zep file option. More advice would be welcome.

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                • #9
                  Originally posted by bratpat View Post
                  Hi again cam3d

                  Great! used the Lumix camera; waited for the sun to go in and took the shots outside; did not crop the reults - and all 26 images loaded OK and Zephyr cameras were set. However, the model when generated (with masking selected) has all of the white paper (uncropped) on which it was standing as part of it. How do I get rid of that. I can't see anything that will do it in the tutorials or the various menu items. I loaded the file into VoxelMaker to get a file for printing anyway but it showed the massive paper base, with jagged edges.
                  You can edit a reconstructed surface in Zephyr using the selection and cleaning tools: https://www.youtube.com/watch?v=38Xo-ukWUhU

                  ---

                  We update 3DF Zephyr fairly regularly and things do change around a bit, but you made the right decision to go for General settings - If you increase the settings you'll also increase the time it takes to process and the gain may only be marginal, or even in some cases the result is worse that otherwise because false features have been detected which lead the reconstruction astray.

                  ---

                  Masking could make things worse for a few reasons:

                  A. The background stays in the same relative position as the subject. In this scenario, it makes no sense to mask the background as the background helps to re-enforce the image matching.

                  B. The subject doesn't have enough features alone and needs some kind of feature rich support for successful image matching (e.g. fine print newspaper underneath)

                  C. The mask is inverted - Make sure that red is subject of interest, and blue is background, ignored.

                  *** There are a lot of reasons that things can go wrong and without seeing the images themselves all I can provide is generalized advice. Feel free to share more images if you'd like more feedback.

                  ---

                  If you're using the free version of 3DF Zephyr the export options are limited to textured mesh, PDF screenshot and saving the .ZEP project. The paid version of 3DF Zephyr Lite has more mesh export options, and the full version of 3DF Zephyr also includes point cloud exports.

                  I hope this helps a bit!

                  Last edited by cam3d; 2022-04-04, 11:48 PM.

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                  • #10
                    Thanks again cam3d

                    I'll try the selection and cleaning tools on a brand new set of photos. I've invested in a small turntable and a camera tripod as I was far from satisfied with the earlier results. I've also found where the export as an .obj option is - not in the obvious (to me) place under Export but in the Textured mesh generation menu - I'm learning. The model I printed as test was junk as the detail was missing on one side, but the rest was really good even in a half scale version, so there are enough features if I get it right. I really do appreciate your help. As a matter of unconnected nterest, my architect son has just completed a major recording studio design for the University of Canterbury in Christchurch. He may get to visit if and when the project goes ahead. It will be part of a very large expansion of their 'Arts' facilities.

                    Best wishes

                    bratpat

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                    • #11
                      bratpat No problem - Small world! Yeah over the past decade or so Christchurch has had a lot of development since the big earthquake there - I've not been to visit since that happened, most of the time I'm in Wellington :-)

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                      • #12
                        Well, cam3D. I thought I was geting somewhere but a week of trying has ended in failure. With a new set of photos taken on the turntable, with a white base, I selected 33 of 44. The Image quality index was constant and quite high for all the shots. When the mesh was generated there were grey 'clouds' scattered around the image, with the bounding box ceiling almost completely covered. I selected the colour and deleted them. Or so it appeared. I saved the textured mesh as .obj and loaded it into Voxelab. the image showed surrounded by little red bits but I tried a print anyway. It was hopeless, the extruder just scattered little curls of filament at base level where the red bits showed so I aborted. I took a screenshot in Zephyr of the image as shown before saving and I did a screen grab on the Voxelab image. I could upload these (or the whole project files)if you wish. I also wonder if a black cover would be better on the turntable? Your advice would be welcome - again..Just remind me how to send you anything.

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                        • #13
                          bratpat No problem - If you have a Google account you can upload the files to your Google Drive and share a download link with us either here or through support@3dflow.net - Alternatively you could use a file transfer service such as WeTransfer. Please send all reference material you can (most importantly, the original images you used for the reconstruction) - The more reference material, the faster I can get back to you with feedback :-)

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                          • #14
                            Thanks cam3d

                            I've put it all in one folder. The Google drive link is https://drive.google.com/drive/folde...Km?usp=sharing

                            I've also sent it to the support address for surety.

                            Best regards

                            bratpat

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