How do you "Add Photos"? (Not a basic question)

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  • LiNo
    3Dflourished
    • Feb 2018
    • 44

    How do you "Add Photos"? (Not a basic question)

    Hi, again. Another "general" level question about process that you might be able to help with. First off, as background, I am a user of the free version of the software and looking to understand the workflow process so that I can make the decision to buy. And also, thank you to those (especially Andrea) that have helped me in the past.

    My intention is to use the software to create a number of models of local landmarks that might be of use / interest to (local) people. The workflow that I envisage is to take a lot of photos, create a model, identify the gaps / holes in the model, go back and take more photos, and add them to the model in order to fill in the gaps. And as a workflow, this is very applicable to the free version as well (take a lot of photos, create a model with 50 but some get kicked out, replace the not-orientated photos with new photos from the set that I took originally) ... the only problem is that I have never been able to add photos successfully, even when there is 100% overlap, with good contrast / patterns. So, I assume that I am doing something wrong, but I'm really not sure what it is.

    Therefore, my question: can you give me relevant guidelines for adding photos (what I should watch out for, what I should aim for, what I should avoid)?

    I know that this is not a simple question with a "one size fits all" answer, but given my lack of success with the process, any and all guidance would be greatly appreciated.

    As a reference point, I share some of the work that I have done in the link below. There are two ZEP files that I would point to, "Plinth 2" and "Plinth 3". They are basically two models that I created from one set of photos, and largely the photos from either should be a good match to points on the other. However, try as I may (adding some from Plinth3 into Plinth2 and visa versa), I have not been able to get a successful "merge"! (The related JPG's associated with the ZEP are burried in Job\JPEG.)

    As usual, thank you in advance.

    Regards,

    Noel.
  • Andrea Alessi
    3Dflow Staff
    • Oct 2013
    • 1335

    #2
    Hi Noel,

    can you please double check the shared link? Thank you!

    Comment

    • LiNo
      3Dflourished
      • Feb 2018
      • 44

      #3
      Apologies Andrea, I'm not sure what went wrong with the link. Could you try this one - I think that it is working correctly.

      Comment

      • Andrea Alessi
        3Dflow Staff
        • Oct 2013
        • 1335

        #4
        Hi Noel,

        thank you!

        Make sure to select more than one camera that is near to the newly added photos. The most common error here is to simply select one or two images and hope for the best. Still, the images must have a good overlap between the existing cameras.

        However i did a quick test and yes, it does fail. I think this is most likely due to the high level of noise in the images. You are probably going to have better luck by feeding the full dataset togheter rather than adding them. Unfortuantely i coudldn't test too much today, but i'll hopefully do some test next monday.

        It's also important to underline that the matching phase will be done with the preset you have used in the original project, so there is no way to "increase" the parameters if zephyr doesn't manage the "add photos" instruction the first time.

        On a side note, try to avoid nodal movement when taking images (it looks like you were stationary and took three images from the same point and simply rotated your camera three times. Next time, try to take three images from 3 different heights, that will lead to better results).

        Comment

        • LiNo
          3Dflourished
          • Feb 2018
          • 44

          #5
          Thanks Andrea. That all makes sense ...except the level of noise - good camera, low ISO, fast shutter speed - that should take care of that right? I have attached one of the photos that was rejected (for easy reference, there is an associated mask aswell but I could not load this, however it is on this link https://1drv.ms/u/s!AgdskftNUq2xi5c-nUfRKTAdoJEM4g).

          Unfortunately feeding the entire dataset in one, breaks the workflow that I had envisaged and I need to have a think about that.

          If you do come across anything on Monday, I would be very grateful for any and all insights.

          Regards,

          Noel.
          Attached Files

          Comment

          • Andrea Alessi
            3Dflow Staff
            • Oct 2013
            • 1335

            #6
            Hi Noel,

            I haven't forgotten about you - this week we're busy at the ISPRS conference so testing dataset is slower than usual. Sorry about that!

            Comment

            • LiNo
              3Dflourished
              • Feb 2018
              • 44

              #7
              No problem at all Andrea. I haven't had a chance to look at it until now and it will be the end of the week before I get to think about it (my day job is getting in the way as well ).

              Thanks again Andrea.

              Regards,

              Noel.

              Comment

              • Andrea Alessi
                3Dflow Staff
                • Oct 2013
                • 1335

                #8
                Hi Noel,

                I had the chance to take a better look at your dataset.

                The problems is ultimately with the quality of your images. Not only they are very dark, but they are also very noisy. This noise creates false matches between the images, with ultimately result in the famous split you mentioned in the other thread and also fails the add of new images on an existing workspace.

                Always zoom in to understand if your images are good enough, as looking them resized for the screen doesn't really shows you the defects in your images


                Click image for larger version

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                Comment

                • LiNo
                  3Dflourished
                  • Feb 2018
                  • 44

                  #9
                  Thanks again Andrea. I'll try this with another group of photos and see how I get on.

                  Regards,

                  Noel.
                  Last edited by LiNo; 2018-06-10, 12:00 PM. Reason: (Just correcting a typo)

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