On 2015年02月23日 8:16 AM, Benjamin Root wrote: > Interesting choices, and I think we are on the right paths (no pun > intended) through the two possible colors. However, I think the same > problem arises that I noted before. Both ends of the colormap are nearly > black to nearly white. IIRC, our perception of luminosity has a much > greater range than it does for chroma. While it is nice to take > advantage of that, I wonder if we are going too far in the luminosity > range? Perhaps these colormaps would be better if the luminosity range > wasn't as full as it is here? > > Ben Root Ben, I was noticing the same thing, except that at least on my screen, the problem is mainly at the dark end, and it varies with the actual set of control points. The very last one, for example (Purple Red Yellow L5-95) has what looks like a fairly linear ramp from end to end on my screen, while "Blue Green Yellow L10-90" lacks contrast on the dark end. I suspect all this will be quite dependent on the particular screen (or printer--including the whole chain of color conversions ending up in ink or toner dots) being used. It doesn't look to me like a problem with the luminosity range as such. We have a highly nonlinear problem here. In any case, this looks like a nice tool. Maybe it can be combined with Nathaniel's code, which shows other aspects of the colormap? Eric