I got an e-mail from X-Rite support this afternoon asking for more information. I sent it off. Meanwhile, encouraged by the fact that I had finally made a profile, albeit a terrible one, I started over. I printed a new 400-sample test target, and was able to measure it with only one bad row. After… [Read More]
Search Results for: star eater
30 bit color
In the early nineties, while I was attending SPIE, SIGGRAPH, and Society for Information Display conferences, I heard a psychologist give a presentation on display bit depth. He claimed that, under the right conditions, humans could distinguish about 400 shades of gray, and that therefore 8 bits of grayscale resolution, which only allows 255 or… [Read More]
Output antialiasing
Let’s review conventional sampling theory. We start with a continuous representation (the real world, as imaged by the lens), filter that to remove spectral components above half the sampling frequency, sample at evenly spaced infinitesimal points, digitize the results, and store them. To reconstruct the input we take the samples, recreate their values and locations,… [Read More]
Antialiasing, part 2
In the previous post, I talked about sampling, aliasing, and antialiasing in the context of sampling a time-varying continuous signal. In this post, I’d like to carry out a similar discussion for the case of instantaneous two-dimensional continuous spatial signals, such as images produced by a lens, sampled by idealized and actual image capture chips…. [Read More]
Blind Spots
Warning: the photographic part of this month’s blog is preceded by a long non-photographic introduction. Feel free to skip ahead. I’ve been shaving for more than 50 years now. During that time, not much changed. Sure, I’ve always used the latest razors — usually from Gillette. The shaving cream, always from an aerosol can, has… [Read More]