Dear Martin, Florian, a nice problem indeed. Just to add complication, it seems to me that this is just a special case of determining the viewpoint from which an artist or a photographer produced an image of a landscape, a monument or other landmark.
Florian's reverse engineering process determining the place from which the image was taken, either with a camera or by human activity as painting, sketching, and so on, is indeed a mathematical process availing of the software Florian indicated, or of other computational methods. This process may still have some approximation depending on the correspondence of the image to reality and to the quality of the other data used, e.g. the 3D model. Coming to the complication, here are two examples where the same process is not based on maths. 1) Pianta della Catena of Florence, 1470. See it here: https://commons.wikimedia.org/wiki/Category:Pianta_della_Catena#/media/File:Francesco_Rosselli_(attribution)._Pianta_della_Catena,_1470.jpg As you can see from the image, the person who produced this perspective map is also included in the picture (it is the small person dressed in red in the bottom right corner), drawing it from an easily identifiable hill. The mathematical approach may not work in this case because in 550 years the city skyline has changed and the drawing was probably imperfect. Nevertheless, identifying the place is almost certain, but we must accept that the drawer’s representation is faithful as regards the place where he did the job, and not just a symbolic indication that the map was made “at bird’s eye” from a high place. A later map (1594) by Stefano Buonsignori mentions the hill from which it was taken - the same as the above-mentioned one - but gives no clue about the *exact* place. Unfortunately I have no reference to good images for this map except this one: https://upload.wikimedia.org/wikipedia/commons/0/02/Pianta_del_buonsignori%2C_dettaglio_138_porta_a_san_friano.jpg which is notable only because the gate is next to my house :) In sum: an old map depicts the point of view; a later one, but still ancient, mentions the place in a generic way; direct observation confirms the place, which appears obvious from the drawings perspective, if you know the town and the surrounding hills (I do). No computer image processing may identify the place because interpretation of the human figure (case 1) or understanding the map title (case 2) are required. There are moreover studies identifying the place with some greater accuracy as being an open space close to a monastery on the said hill. Is this still a data Evaluation? 2) The second case concerns the interpretation of art historians. For example I found that for a painting (1494) by Albrecht Dürer titled “The mill” https://it.wikipedia.org/wiki/Albrecht_D%C3%BCrer#/media/File:Durer,_il_mulino.jpg an art historian stated that “the painter was standing on the high northern bank of the Pegnitz river, looking towards south”. No idea why this art historian states so. Dürer painted also many watercolour paintings in Trentino, and there is now a cultural route titled “Albrecht Dürer Path” where visitors may stop at designated points and look at the landscape from the (reconstructed) viewpoints of the painter https://www.trentino.com/en/leisure-activities/mountains-and-hiking/hiking-in-autumn/albrecht-duerer-path/ I don’t think they used computers to create it. In conclusion, maybe the viewpoint reconstruction is a more general process: an Evaluation if it can be done/supported mathematically, something else (?) if computation is not feasible but other means can be used with reasonable trustworthiness. Is there a superclass fit for all cases? Best Franco Prof. Franco Niccolucci Director, VAST-LAB PIN - U. of Florence Scientific Coordinator ARIADNEplus Technology Director 4CH Editor-in-Chief ACM Journal of Computing and Cultural Heritage (JOCCH) Piazza Ciardi 25 59100 Prato, Italy > Il giorno 27 ott 2021, alle ore 19:21, Martin Doerr via Crm-sig > <[email protected]> ha scritto: > > Dear Florian, > > Nice Problem! Actually I do not regard it a Simulation, because it does not > introduce theories to extrapolate into the future or to fit to observational > data for theory testing. I think it is simply data Evaluation, which results > in an estimate for a place. I'd regard the calculated viewpoint as a > declarative E53 Place P168 defined by : the calculated value, which P189 > approximates the phenomenal place of the image taking activity. The direction > of taking an image is not modeled in the CRM yet as well as some other > parameters of observations. > > In my opinion, the image itself can be seen as a measurement of optical > qualities of a section of a physical feature, the surface of earth, or an > observation in the case of painting. Both would "P138 represent" this > section. In CRMdig, we took digital photos as a kind of composite Dimension, > because it provides quantitative light emission data, but we did not > consolidate this with taking the image as a Visual Item, a kind of > Information Object. This is not a contradiction. > Both, the painting and the photo can represent identifiable details and > landmarks that allow for matching them with reality, or an assumed common > reality. > > So far, a quick thought. I think, a nice issue, to elaborate the Dimension - > Visula Item question, view directions and sections of physical features > defined by view focus. > > Best, > > Martin > > On 10/26/2021 10:58 PM, Øyvind Eide via Crm-sig wrote: >> 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]>: >>> >>> 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 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 >>> >>> 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] >>> http://lists.ics.forth.gr/mailman/listinfo/crm-sig >> >> >> >> _______________________________________________ >> Crm-sig mailing list >> >> [email protected] >> http://lists.ics.forth.gr/mailman/listinfo/crm-sig > > > -- > ------------------------------------ > Dr. Martin Doerr > > Honorary Head of the > > Center for Cultural Informatics > > Information Systems Laboratory > Institute of Computer Science > Foundation for Research and Technology - Hellas (FORTH) > > N.Plastira 100, Vassilika Vouton, > GR70013 Heraklion,Crete,Greece > > Vox:+30(2810)391625 > Email: > [email protected] > > Web-site: > http://www.ics.forth.gr/isl > _______________________________________________ > Crm-sig mailing list > [email protected] > http://lists.ics.forth.gr/mailman/listinfo/crm-sig _______________________________________________ Crm-sig mailing list [email protected] http://lists.ics.forth.gr/mailman/listinfo/crm-sig
