erdmann

4 ms·

1.
by erdmann 4y ago
I would also like to sing the praises of nip2. I use it constantly in my work with enormous images at the Rijksmuseum. It's backed by libvips, which means that it offers a delightful combination of insane speed and unlimited image si
2.
by erdmann 5y ago
Yes, it's almost the exclusive format for cultural heritage object documentation in museums (I'm Senior Scientist at the Rijksmuseum). It's wonderfully versatile in terms of number of bands, storage format (uint8, uint16, f
3.
by erdmann 5y ago
Ouch. Indeed. Thanks for noticing this. I've reported it to our web people. It's 925 000 px × 775 000 px which is 717 gigapixels (9 zeros).
4.
by erdmann 5y ago
We have collected data in several imaging modalities: RIS-VNIR (reflectance imaging spectroscopy, visible and near infrared (380 nm – 950 nm) in 3 nm bands), RIS-SWIR (same, but from 900 nm – 2500 nm), UV-induced visible fluorescence, MA-X
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by erdmann 5y ago
Fair enough. Its utility is mainly for serving as a virtual microscope for conservation purposes. For example, here [1] is a lead soap [2] particle up close, here [3] is a very detailed view of the dog showing exposed canvas, and here [4]
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by erdmann 5y ago
Perhaps it's intended to disambiguate it from the 20 µm resolution photo we released in May 2020 (the new one is 5 µm sampling resolution, so 16 times the pixel count). From the title alone one might dimly recall that past headline an
7.
by erdmann 5y ago
Glad to see this getting exposure on HN. I gave a PyCon keynote [1] last year about how this was done. I've also put the image online in my own viewer [2], which has a few additional features: it encodes the viewing location in the
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by erdmann 6y ago
The very limited depth of field of a microscope necessitates doing depth stacking for every field of view. This is done automatically by the apparatus. As a side effect, it gives a heightmap, but with the lens used for the whole-painting
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by erdmann 6y ago
Yes, because the surface isn't flat. At these magnifications, any given field of view may be tilted toward one of the light sources, changing the relative contribution of the specular reflection off of the varnish as well as the refle
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by erdmann 6y ago
Yes, and the vignetting pattern isn't so much the problem. It's a color distortion problem (spatially varying chromaticity rather than brightness that is not just a function of the position within the field of view but also of
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by erdmann 6y ago
Yes, because the scan is intended to study and document the painter's technique as well as the state of conservation of the paining. Looking into the abraded painting near cracks, for example, we can see a layer structure that is like
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by erdmann 6y ago
I worked on this project. The images were indeed captured by a 3D microscope in about 9000 separate captures with non-uniform illumination, so this isn't so much a stitching artifact as it is an illumination artifact. The specular co
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by erdmann 6y ago
Thanks! Creator of the image and the viewer here. The viewer is a fork of OSD I made in approximately 2012 to add the functionality that I call the "Curtain Viewer".
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by erdmann 6y ago
Hi, I'm the creator of the image and of the Curtain Viewer technique and software. Please note that this is hosted on my personal AWS and that I pay the hosting costs out of pocket.