I find that the way that the spectrum is displayed (where the levels are shown with different colors of the same intensity) makes the background noise stand out too much and tends to obscure the foreground. It would be nice if I could choose e.g. a grayscale representation such that I could achieve something like this: http://www.xeno-canto.org/recording.php?XC=13187

When I analyze that file with spek, the background noise along the bottom (especially the parts rendered as greens and blues that are supposed to represent a significantly lower level) tends to obscure the foreground pattern.

Thanks for the report, definitely going to implement this after 1.0

Issue 37 has been merged into this issue.

Just FYI, here's the patch I'm currently using to make spek draw a monochromatic spectrogram. I realize that this patch isn't necessarily appropriate for upstream, but I thought I'd just attach it here to show approximately what I'm trying to achieve.

Yes, that's what I had in mind - just using a linear scale for all RGB components.

Actually, after playing with it a little more, I've found that making the scale slightly non-linear is a little bit nicer at de-emphasizing the background noise. e.g.:

r = g = b = (1.0 - level*level);

Of course means you lose some resolution at the lower end of the scale. but for my use it seems a bit nicer.

This issue has been moved to https://github.com/alexkay/spek/issues/17