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Nice. Colorspace profile management across the distribution pipeline is still a disaster. It would be nice if: 0. The full stack of end-user display down throu

Nice. Colorspace profile management across the distribution pipeline is still a disaster. It would be nice if: 0. The full stack of end-user display down through distribution, editing, and "film" camera applies faithful color management. 1. Every scene contained a hidden color calibration frame that was recorded on-set holding a proper calibration sheet that the end-user's display could apply dynamic color-correction to produce color calibrated to the average lighting conditions that existed on-set. 2. The end-user can choose whether to apply just 0. or also 1. There is another problem: in filming or editing, by applying color filter "looks" there is currently little in the way of assurances that downstream will faithfully reproduce what was intended. Colorspace profiles were and are a great advance, but they need to be measured, calibrated and validated all the way down so that they're useful. PS: This article also reminded me of an attack that could reproduce almost an entire image from diffuse reflections of old-style scanned CRTs/TVs, e.g., that ghostly blue glow of TV watching visible from outdoors, but also that imperfect reflections of CRT computer monitors could reveal their contents.

blevin 7y ago
Did the diffuse reflection reconstruction rely on high speed photography? Or a special geometric setup of the reflector? Trying to think of how this could work.
- pdkl95 7y ago
  It sounds like "Dual Photography". https://dl.acm.org/doi/10.1145/1186822.1073257 https://dl.acm.org/doi/10.1145/1186822.1073257 "We present a novel photographic technique called dual photography, which exploits Helmholtz reciprocity to interchange the lights and cameras in a scene. With a video projector providing structured illumination, reciprocity permits us to generate pictures from the viewpoint of the projector, even though no camera was present at that location." I recommend watchign the video from the paper for good explains and demonstrates the technique. It's very impressive work. https://www.youtube.com/watch?v=p5_tpq5ejFQ https://www.youtube.com/watch?v=p5_tpq5ejFQ
  - VohuMana 7y ago
    Ok that trick with the playing card was cool. I'm impressed by the math that is behind this concept and all I could think about while watching it is every cheesy crime show calling out "enhance"
  - beojan 7y ago
    So the catch is that you have to be in control of the projector.
pbhjpbhj 7y ago
The CRT attack works because it's a progressively scanned image, so each pixel is being produced at a distinct time. Take the image intensity of a screen from a telescope a mile away, write the pixels, jiggle the offset and you have an image. I'm sure it was harder than that in practice.

blevin 7y ago

Did the diffuse reflection reconstruction rely on high speed photography? Or a special geometric setup of the reflector? Trying to think of how this could work.

pdkl95 7y ago
It sounds like "Dual Photography". https://dl.acm.org/doi/10.1145/1186822.1073257 https://dl.acm.org/doi/10.1145/1186822.1073257 "We present a novel photographic technique called dual photography, which exploits Helmholtz reciprocity to interchange the lights and cameras in a scene. With a video projector providing structured illumination, reciprocity permits us to generate pictures from the viewpoint of the projector, even though no camera was present at that location." I recommend watchign the video from the paper for good explains and demonstrates the technique. It's very impressive work. https://www.youtube.com/watch?v=p5_tpq5ejFQ https://www.youtube.com/watch?v=p5_tpq5ejFQ
- VohuMana 7y ago
  Ok that trick with the playing card was cool. I'm impressed by the math that is behind this concept and all I could think about while watching it is every cheesy crime show calling out "enhance"
- beojan 7y ago
  So the catch is that you have to be in control of the projector.

pbhjpbhj 7y ago

The CRT attack works because it's a progressively scanned image, so each pixel is being produced at a distinct time. Take the image intensity of a screen from a telescope a mile away, write the pixels, jiggle the offset and you have an image. I'm sure it was harder than that in practice.