Dear colleagues, thank you so much for all your thoughts and input!
The examples by Franco indeed illustrate the problem very well. We also do have many images that are composites of different views. The engineers at Smapshot may come up with ways to accommodate this, for example by distorting the image or by enabling a segmented georeferencing of an image. We also have landscapes where we are quite certain that their creator has never actually seen the view themself, but has copied a landscape from another artist. So we can't make any statement about the location of an artist when creating an image. In the case of photographs we can make such statements and would be able to use the measurement approach that Martin described. In general, I would tend to represent in data what we know and only in a second step what we conclude from that knowledge. Øyvind's suggestion therefore sounds plausible, too. We create a 3D model, and from this model we conclude something, namely a hypothetical viewpoint of an observer. I have to give it some thought how to represent this in a data model without creating too many statements that are not grounded in available data, but I think it might be a good direction for this particular problem. Thank you all again, best wishes, Florian > On 31. Oct 2021, at 12:12, Øyvind Eide <[email protected]> wrote: > > Dear Florian, > > in addition to the comments made by others, which makes a lot of sense too, I > would offer the additional perspective that the resulting 3D model (with the > added canvas) can be seen as a collage of the source 3D model and a digital > reproduction of the photography / painting — thus as a work is the bringing > together, based on certain rules and principles, of two works. > > I think this adds a different perspective than some of the others mentioned. > Which perspectives to focus on when modelling such processes is a pragmatic > choice. > > All the best, > > Øyvind > >> Am 27.10.2021 um 12:18 schrieb Florian Kräutli via Crm-sig >> <[email protected] <mailto:[email protected]>>: >> >> Dear Øyvind, >> >> Thank you very much for your input! To answer your questions: >> >> 1. Yes, the tool uses a 3D model of a landscape (based on Cesium: >> https://cesium.com/ <https://cesium.com/>) >> 2. Yes >> 3. Yes. The tool positions the image in a 3D landscape so that from the >> calculated viewpoint, the 2D image aligns with the 3D landscape. The tool >> also outputs a glTF of what I assume is the canvas position in the >> coordinate system: >> https://smapshot.heig-vd.ch/api/v1/data/collections/36/gltf/204037.gltf >> <https://smapshot.heig-vd.ch/api/v1/data/collections/36/gltf/204037.gltf> >> (though I'm not familiar with this file format) >> >> I should mention that I also discussed this issue via Slack with Matteo >> Lorenzini. Nicola Carboni already prepared a model to document the >> perspective over a place by a person, documented as the point of observation >> by an actor. We concluded that we could apply that model also in this case. >> However, I would be very interested in your thoughts on how to treat it on >> the level of the 3D model. That might help me to model the data closer to >> the actual process of how it was obtained. >> >> Best wishes, >> >> Florian >> >> >>> Subject: Re: [Crm-sig] Modelling a simulated view on a physical space >>> Date: 26. October 2021 at 21:58:32 CEST >>> To: Florian Kräutli <[email protected] >>> <mailto:[email protected]>> >>> Cc: [email protected] <mailto:[email protected]> >>> >>> >>> Dear Florian, >>> >>> thank you for this interesting puzzle! >>> >>> Before I venture into concrete suggestions, allow me to ask some question >>> in the form of assumptions you can confirm, reject, or discuss: >>> >>> The establishment of a hypothetical viewpoint is used to establish a >>> location of the canvas. That means the following: >>> >>> 1. There is a 3D model of a landscape where each point (also those making >>> up lines and polygons) are normal (x,y,z) coordinates in some coordinate >>> system. >>> >>> 2. The hypothetical/assumed viewpoint of the photographer or the painter is >>> a point in the same coordinate system. >>> >>> 3. Each point of the canvas (representing a painting or a photography) >>> being put into the landscape is a point in the same coordinate system. Thus >>> the canvas as a whole is an area in that coordinate system. >>> >>> If this is so, we might very well talk about something added to a >>> pre-existing 3D model. If not, I would be happy to be enlightened and >>> hopefully manage to dig further. >>> >>> All the best, >>> >>> Øyvind >>> >>>> Am 26.10.2021 um 10:28 schrieb Florian Kräutli via Crm-sig >>>> <[email protected] <mailto:[email protected]>>: >>>> >>>> Dear all, >>>> >>>> I have a data modelling challenge I would need some advice with. >>>> >>>> We work with a collection of geographic depictions of Switzerland. This >>>> includes photographs, paintings, prints, sketches, etc. We collaborate >>>> with Smapshot <http://smapshot.heig-vd.ch/> who developed a method for >>>> aligning landscape photographs with a 3D model of the physical landscape. >>>> An example from our own collection can be seen here: >>>> https://smapshot.heig-vd.ch/visit/204037 >>>> <https://smapshot.heig-vd.ch/visit/204037> >>>> >>>> Using this method we can determine the possible viewpoint of a >>>> photographer when taking a picture, or the viewpoint from which an artist >>>> may have produced sketches of a landscape. In terms of data, we obtain the >>>> simulated position and view of the photographer/artist as coordinates >>>> (lat/long), altitude, azimuth, tilt, roll and focal view. >>>> >>>> I'm debating now how to model this obtained data in CIDOC-CRM. I would >>>> suggest a S7 Simulation or Prediction for the process of using the >>>> Smapshot app to determine a viewpoint of an image. This process P140 >>>> assigns an attribute to a E36 Visual Item, namely that the E36 Visual Item >>>> (the image) P138 Represents a view. What is this view? Can we say it is a >>>> E53 Place? Or is there a more suitable entity for describing such a >>>> (simulated) view? >>>> >>>> One could also say that the data defines a E53 Place from which an image >>>> has been created. However, while we can say this with some degree of >>>> certainty for photographs, a painting of a landscape might have been >>>> created using a combination of several viewpoints as well as, of course, >>>> use of imagination on and off-site, so I would be hesitant to make a >>>> statement about the physical location of an artist when creating a >>>> painting. >>>> >>>> I would be grateful for your input! >>>> >>>> All best, >>>> >>>> Florian >>>> >>>> _______________________________________________ >>>> Crm-sig mailing list >>>> [email protected] <mailto:[email protected]> >>>> http://lists.ics.forth.gr/mailman/listinfo/crm-sig >>>> <http://lists.ics.forth.gr/mailman/listinfo/crm-sig> >>> >>> >>> >>> _______________________________________________ >>> Crm-sig mailing list >>> [email protected] <mailto:[email protected]> >>> http://lists.ics.forth.gr/mailman/listinfo/crm-sig >>> <http://lists.ics.forth.gr/mailman/listinfo/crm-sig> >> >> _______________________________________________ >> Crm-sig mailing list >> [email protected] <mailto:[email protected]> >> http://lists.ics.forth.gr/mailman/listinfo/crm-sig >
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