Legacy ImageMagick Discussions Archive

Thanks for the link. Their definition of peak ...

A local peak is a data sample that is either larger than its two neighboring samples or is equal to Inf. Non-Inf signal endpoints are excluded. If a peak is flat, the function returns only the point with the lowest index.

... is very simple. Far too simple for my purposes, as a typical photograph with a noisy histogram would have a very large number of peaks. Various alternative definitions might be used, such as smoothing the histogram (or reducing the number of buckets) before finding peaks. I use a sliding window across the histogram, with default width 10% of histogram. Then a series of rules (between three and seven) determine where the peaks lie.

I linked to the Matlab help pages for the discussion on the function's arguments, "Prominence", and links to "Peak Analysis" and "Find Peaks in Data". Anyway, it was just to give you and fmw42 context to where my thoughts lie. I look forward to your implementation .

The cygwin-built IM creates files with permissions different from the Windows default (a looser one). Any idea how I can prevent this?

Re: CYGWIN Puzzle → What I know so far and might be why I've been having trouble with snibgo's scripts:

1. Re: Permissions problem. I found a simple workaround: due to inheritance, the permissions are correctly administered when I write to a different directory than the current one.
2. On my system, CYGWIN-built binaries follow Bash conventions; they don't understand backslashes (e.g. Windows-styled paths) or windows environment variables (%sssOPTION%).

BTW snibgo, I noticed that your Histogram peaks page is up now . Scripts like histoPeaks.bat use binaries that aren't readily available (cPrefix). Hence, I can't try out some of your srcripts.

2. Yes, paths are a pain in the neck. But environment variables such as %sssOPTION% are translated by the command processor, such as Windows CMD. The translation is passed to the binary program, so it doesn't matter whether the binary is Windows or Cygwin.

Yes, scripts use binaries that I don't publish. The cygwin toolset probably contain tools that are better than those binaries.

2. Unfortunately, this won't work on my system: Currently, I have to modify sigSetSd.bat to write to a file that I can access later using It doesn't make much sense to me but it happens with the slashes too when I use %im% or %imdev%, which confuses the heck out of me.