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leszekp

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leszekp last won the day on January 6

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About leszekp

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  • Interests
    Archaeology of the American Southwest and West.

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  1. leszekp

    RTI Viewer foriPad ?

    Used to be - unable to find any reference to it on the iTunes store.
  2. leszekp

    RTI Builder Unknown error

    The old ptmfitter had an effective image size limit of 24 megapixels on Windows, even on systems with lots of RAM. The new ptmfitter from Kirk Martinez' group has no problems handling images up to 100 megapixels in size; I don't go any higher because the RTIViewer software has problems above 100 megapixels. https://custom-imaging.co.uk/software/
  3. leszekp

    The Format of imported images

    Somewhere online there used to be a description of the ptm format, but that appears to have disappeared. It should be described in the original Malzbender paper about PTM. Don't know if I've ever seen anything comparable for the rti format, but the original paper about HSH fitting should give you some information. You might contact CHI directly for the source code for the hsh fitter, and that should give you information about the storage format for the rti files. Not sure exactly what kind of useful information you expect to get from the files. They just store the fitting coefficients for every pixel (along with the RGB date) that's used to calculate normals, both of which are used by the viewer to display the image and the effects of changing the lighting angle.
  4. leszekp

    The Format of imported images

    Both fitters (PTM and HSH) only take jpg files. If you have uncompressed images, you will have to convert them to jpg format. Just select the highest quality jpg setting for the best results. I convert RAW files to JPG format all the time, and they work fine.
  5. leszekp

    An alternative for controlling 3W leds

    I had noticed that it was somewhat conductive, probably because it's full of graphite. But didn't see any effects in my system.
  6. leszekp

    tiny objects

    You might also try stopping down even further to F11, to get a better depth of field. The other issue is whether the skull has enough details on it for Photoscan to be able to match points between different photos. If not, you might try shooting RAW, then increasing contrast/clarity in the photos to accentuate whatever details are present.
  7. leszekp

    Truvis

    Yours for the low, low price of $24,000 (not including camera). Or you can build your own for less than 5% of the cost: https://hackaday.io/project/11951-affordable-reflectance-transformation-imaging-dome
  8. leszekp

    Truvis

    Hmmmm... https://broncolor.swiss/scope/ https://truvis.ch/ For a brand-new breakthrough visualization technology, it looks awfully familiar ...
  9. leszekp

    The size of dome

    For lithics, I use the normals mode, then manipulate the RGB channels individually for maximum contrast. Convert to grayscale, do some more advanced contrast work (clarity/CLAHE), sharpen it up, and you get a fantastic image of the flake scars on the stone tool, better than any hand drawing.
  10. leszekp

    An alternative for controlling 3W leds

    Running the 3W LEDs continuously is definitely a bad idea when there's no heat sink. The solder melting point is less than 200C. They only need to be on long enough to take your photo, which shouldn't be more than a few seconds. While many of these are rated up to 1A, the usual nominal operating current is 700mA, at which current level they will stay quite a bit cooler. Intensity is a bit lower, and the exposure time will be slightly longer, but it's not going to be a huge different (a few tenths of a second).
  11. leszekp

    An alternative for controlling 3W leds

    I had the same thought a few years ago, but decided that it didn't make sense. You're fitting a curve to the (primarily) Lambertian lighting scattering at every point based on the lighting angle. If you change the lighting intensity with angle, you'll skew the lighting curve to fit to those higher intensities, which will introduce errors. Shadows are areas where the main light source is blocked, so any signal from those areas is a result of scattered light within the dome, which doesn't really offer you any useful signal for curve fitting.
  12. leszekp

    An alternative for controlling 3W leds

    You might give this site a look (not that I'm biased or anything): https://hackaday.io/project/11951-affordable-reflectance-transformation-imaging-dome
  13. leszekp

    The size of dome

    This is a useful rule-of-thumb, but I've found that you can sometimes stretch this a bit. I just did RTI on a 7" long Mayan lithic blade inside a dome with a 9" light to object distance, and got a more than acceptable photo out of it (with a bit of work in Photoshop).
  14. leszekp

    Embedding Rti viewer into Wordpress

    You can embed it in a WP page using an iframe tag. Example: <iframe src="http://swvirtualmuseum.nau.edu/wp/RTI/Powell_Watch_2.html" width="600" height="640" frameborder="0" allowfullscreen="allowfullscreen"></iframe> View the result on this page: http://swvirtualmuseum.nau.edu/wp/index.php/national-parks/grand-canyon-national-park/rti-gallery/
  15. leszekp

    Difficulty launching RTI Builder

    I had the same issue with Windows Defender on one of my computers. You'll need to set an exception/exclusion for this file: https://support.microsoft.com/en-us/help/4028485/windows-10-add-an-exclusion-to-windows-defender-antivirus
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