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Dave Martin

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Dave Martin last won the day on August 28 2020

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About Dave Martin

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  1. Thanks Krl, I was worried when you said you were 'cropping' them - I thought you were cropping them out of the image before processing! - those boxes are just to define the search area. Secondly, just looking at your original image, I have a few observations of which only the first couple may relate to the problem you have experienced. 1. The background on which the spheres are sitting (or is behind them) looks very close in colour to the spheres, because you're using a photograph where the grey card or background is in shadow - you're not doing the circle-edge detection any favours, its trying to detect black on near-black! 2. The illumination in the shot you kindly supplied looks rather low - the recommended light positions are no lower than 15 degrees to the plane of the object, and no higher than 65 degrees to the plane of the object. 3. The highlight-detection method of RTI generation depends on accurate detection of the highlight on the sphere as each frame is processed, and using that to deduce the direction from which each frame was illuminated. The light should be reflected as a 'spot', as near to a point - but the light looks to be more like patches on your spheres? (maybe either over-illuminated or something like a flood-light used rather than as close as you can mange to a point source). 'Wide' sources won't affect the sphere detection but it will give less-distinct shadows and hence degrade the final result. 4. The whole process depends on each frame having, as close as you can, only one direction of illumination. Looking at your sample image, it looks as if the are other light sources or something out of shot that are throwing multiple direction illumination on the spheres? - that shouldn't affect the feature detection but it will degrade the final result. I'd highly recommend that you go through the RTI Capture Guide which CHI publish at http://culturalheritageimaging.org/What_We_Offer/Downloads/RTI_Hlt_Capture_Guide_v2_0.pdf - have a look at how the spheres and illumination appear in successful use. CHI also have tutorial data sets on their web site which are known to work, as well general practise they allow you to see how successful capture looks. cheers/Dave
  2. Krl, Can you post one of your source images with the spheres, and then a screenshot of where you say you "crop out the spheres"? Dave
  3. Phil, I have captured room-sized interior spaces, but haven't imaged or scanned a factory as such; so these are a few generic thoughts, and much depends on the context, and what your deliverables are. If it is a factory occupied by equipment, pipes, ducting, conveyors, etc. then it is difficult for both laser scanners and photogrammetry as there will be numerous areas which are occluded (hidden) behind/above/below obstructions, so you'll only be able to capture the nearest face. Photogrammetry can struggle more because the processing software needs to 'see' and 'recognise' something in multiple images. With a laser scanner (at sufficient point density) you can pick up, say, a number of points on the nearest faces of say a duct, sufficient to estimate its diameter or section. Furthermore, you only need space for a single laser shot to get 'between' two items to capture at least a point behind - whereas with photogrammetry to derive that point you need it in at least two images, ideally more, and if you move viewpoint to take the next frame, you may lose sight (and even if you can see it, is there sufficient to triangulate its location?). If it is an empty space, then that is probably more achievable with photogrammetry subject to two factors - illumination and detectable tie points. In small rooms or ships' compartments for example, a ring-flash can be a useful illuminator; but for a cavernous space you will be dependent on existing lighting so you may be advised to use a tripod (so as to have as long an exposure as you can) and shoot from camera stations. Also in a cavernous space, especially if uniform, you may have difficulty when processing in establishing sufficient number and quality of tie points between your images so use of targets (ideally coded) would be worth considering - you could also use them as scale-markers. Although there may be some in the Cultural Heritage world who have imaged/scanned factories or comparable spaces, I would suggest that it might be productive for you to pose your query in more generic fora such as Agisoft's own forum, or FaceBook groups such as that dedicated to MetaShape or the generic 'LiDAR and Photogrammetry Review'. Dave
  4. Interesting open-access article on ways to extract features from photogrammetry models: https://www.cambridge.org/core/journals/antiquity/article/3d-contour-detection-a-nonphotorealistic-rendering-method-for-the-analysis-of-egyptian-reliefs/3DF1102C5016098C8D14D203D9D41C7C
  5. Dag-Øyvind, I can't help directly, but a couple of suggestions, as it looks like it might be a graphics driver related issue: 1) It might help if you gave some details of your laptop make/model, operating system, and what graphics card it has. 2) Is the problem / that screenshot from the laptop's internal screen, or when using an external monitor? 3) If you haven't done so already, might be worth trying with an external monitor 4) It sometimes can be illuminating to temporarily try putting your laptop (internal screen and/or external monitor) into a different lower resolution 5) It would be worth checking for updates for your graphics card - from the operating system, and from both the laptop manufacturer and the graphics card manufacturer. 6) You say this is all projects, do you have a project which you can view OK on one PC but when you copy the files (or access over network) they give this faulty display? MVH Dave
  6. MBennett, I don't know if there is any way you can synchronise or import chunks, but one possibility is if you have network connectivity, it might be possible to have various clients accessing one PostgreSQL database. Dave
  7. Ale, Particularly with PTM models, there are a range of visualisation aids, such as specularity, built in to the viewer already. Re "Metallic" - not sure what you're meaning exactly. RTI cannot perform any analysis of the subject's elemental composition by itself - you may get some clues from the photograph visual wavelength spectra, but you will get more - for bulk composition especially - using, say, XRF (X-Ray Fluorescence) - and hand-held XRF is becoming more common. Re "Roughness", there is work aplenty on machine vision assessment of 'roughness' as a production quality tool, using direct and scattered light and sometimes fractal analysis, but that is usually associated with prior reference data acquired with a similar part of known RA and RZ. I think it would be good if you could maybe explain your target / sample type / size / what you're trying to investigate. Dave
  8. Ale, I've posted an answer in the RTI dome acquisition section of the forum, suggest you might delete this duplicate question. Dave
  9. Ale, The idea of using addressable LEDs is definitely attractive; but I think it would harder than you think, and not very successful, to use those strips. 1) Those LEDs are not bright - you need a reasonably power light source to cast the shadows for the RTI process - or you need very long exposure times and noisy high ISO. 2) If you use such a strip, you will only be using a fraction of the LEDs 3) You can't just use, say, a sequential controller, you will need some form of programmable control - be it Arduino or PC or AVR or even TTL logic - to switch on the appropriate LED, let it settle, then fire the camera, and then repeat. Or, if your off-the-shelf controller allows you to specify switch on LED 74 at R=..G=..B=.. then you could do that manually, fire the camera, switch off LED 74 and then switch on, say, LED 81. 4) If you use such a strip, you will struggle to get the LEDs in the optimum position unless you cut the tape and solder fragments together (not actually difficult at all) and that is an attractive possibility (subject to note 1 above though) I have actually tried using strips similar to this as donors for a mini-dome, chopping into individual LEDS, placed appropriately around a dome and chaining them with soldered jumpers (light for data in/out, slightly heavier for power and ground, with extra power tapped-in periodically). However, results were not great due to low light output from individual LEDs. Dave
  10. Jackie, Regret I can't help directly (my last Apple PC was Apple-II on which I used UCSD Pascal for my PhD research!) but when you say you have removed the newest version of Java, I just wonder have you been able to remove all versions of Java. Certainly on Windows and some -ix operating systems, you can have multiple Java versions installed, so it is possible that although you removed one (the newest), there might be another slightly older, but still too new, version installed. One other thought if you can't resolve the MacOS installation is could you maybe run a virtual PC and clean-install windows thereon to give an environment to host required version of Java and then install RTI software in that virtual machine? Dave
  11. Luke, This rings a bell for some years ago - I have a faint recollection someone found a case-sensitivity. 1) Suggest you rename your files ".jpg" and try again. If that fails, 2) Have you ever been able to make a PTM before? if so can you try that image set again? 3) If this is the first time you're trying to make a PTM, suggest you download the Fish Fossil image set from the CHI website and try them, as they are known to work OK with both HSH and PTM fitters. Dave
  12. Hi Fionn, A couple of thoughts / questions. 1) Generally, it is a good idea to give a little info as to operating system and version and 32/64 bits etc. 2) Can you grab a screenshot of the box on the RTI builder screen where you specify the location of the PTMFitter, like the attached please? 3) On this laptop (Windows 7-32 bit) my location is "C:\RTIbuilder_v2_0_2\Fitters\PTMfitter\PTMfitter.exe". One thing that I wonder is your error message just ends "... /PTMFitter" but on my Windows machine the ".exe" is recorded and shown in the path. Dave (from Fionn mac Cumhaill's rock in the Irish Sea!)
  13. SpeiVerta, OK, I think may best not to try to climb Everest as first mountain! CHI have provided a sample set of images - which definitely work. If there is any problem, still doing this, there is no point going on to your relatively-massive pictures. Please forgive me if these duplicate what you know or have tried, but this is the simplest set of steps, could you try these as they definitely work. Please try these and let us know if you successfully make and view a basic HSH RTI as below. Dave On your PC, if you don’t already have one, make a folder RTI at the top level on your C: drive, and within that, make a folder Fish_1000 so you end up with C:\RTI\Fish_1000 Download the Fish_1000 set of example files from http://culturalheritageimaging.org/What_We_Offer/Downloads/Process/ And then – somewhere else on your PC - expand the fish_fossil-data-set_1000.zip file. In the zip file, down one level, you will see a folder jpeg-exports Copy that folder and its contents into C:\RTI\Fish_1000 so you end up with C:\RTI\Fish_1000\jpeg-exports which will contain 36 photographs named fish_fossil_01.jpg through fish_fossil_36.jpg Start RTI Builder In the Project Name box, type Fish_test In the Operation Sequence block, click on the first option – Highlight based (HSH Fitter) Then click the [Start new project] button On the Image selection screen which opens with an initial blank list, click the [Open folder] button at the right-hand edge of the screen In the Windows selection box which pops-up, it usually seems to default browsing to ‘My Documents’. Click on the ‘Computer’ icon (fourth one down) in the left-hand bar Double-click on C: Double-click on the RTI folder Double-click on the Fish_1000 folder Then click [Open] (N.B. please don’t click on the ‘jpeg-exports’ folder) You should then see a pop-up ‘Loading images’ with a progress bar When all the images have loaded, you should then see 36 images in the selection pane after which you should be able to proceed with RTI processing; and as you proceed with building your RTI model, you should see an xml and other folders appear in the project folder, so eventually, if you just proceed (using default options and not cropping) you will have: C:\RTI\Fish_1000\assembly-files C:\RTI\Fish_1000\finished-files C:\RTI\Fish_1000\jpeg-exports C:\RTI\Fish_1000\Fish_test.xml and your finished RTI will be C:\RTI\Fish_1000\finished-files\ Fish_test_1000.rti You will then have an HSH RTI which you should try to open with the viewer C:\RTI\Fish_1000\finished-files\ Fish_test_1000.rti
  14. SpeiVerta, Apologies that I can only reply in English. I can see there is definitely a problem, the size - as read by the HSHfitter - is enormous. The height and width used by the HSH fitter should, with no re-size, be the same as the 'Actual size' (see attached screenshot). It may well be that your images are too big for that HSH fitter, there are other options if that is the case but some questions/suggestions that may help identify the problem: 1) Did this work before for these exact images and just stop now? 2) Is this the first time you tried to build an HSH RTI? 3) Have you successfully made an HSH RTI for other images of your own? 4) IF you made one OK before, if you go back to that set, does it still work? 5) Have you tried making an HSH RTI with the sample set of fish-fossil images you can download from the CHI website? 6) If you can make the fish-fossil OK, it may be your images or the memory demand are too big. How many images are you using? / what is their size in MB? 7) If you only process, say, eight of your images, does the same happen? 8) If you - just for testing - make a copy of your images with smaller resolution, say 1/4 size, does that work? 9) Also, It is always useful to also report what operating system/version you are running?; also the source of your images? Dave
  15. David, Those modes are available if you generate via PTM rather than HSH. Dave (IOMNHAS)
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