unu-heq - Man Page
perform histogram equalization
Synopsis
unu heq -b,--bin <bins> [-s,--smart [<bins>]] [-a,--amount <amount>] [-m,--map <filename>] [-i,--input <nin>] [-o,--output <nout>]
Description
Perform histogram equalization. If this seems to be doing nothing, try increasing the number of histograms bins by an order of magnitude or two (or more). Or, use unu-gamma(1) to warp the values in the direction you know they need to go. Either of these might work because extremely tall and narrow peaks in the equalization histogram will produce poor results.
- Uses nrrdHistoEq
Options
- -b <bins> , --bin <bins>
# bins to use in histogram that is created in order to calculate the mapping that achieves the equalization. (int)
- -s [<bins>] , --smart [<bins>]
# bins in value histogram to ignore in calculating the mapping. Bins are ignored when they get more hits than other bins, and when the values that fall in them are constant. This is an effective way to prevent large regions of background value from distorting the equalization mapping. (optional int); default: “0”
- -a <amount> , --amount <amount>
extent to which the histogram equalizing mapping should be applied; 0.0: no change, 1.0: full equalization (float); default: -t <type> , --type <type> output type; default: “1.0”
- -m <filename> , --map <filename>
The value mapping used to achieve histogram equalization is represented by a univariate regular map. By giving a filename here, that map can be saved out and applied to other nrrds with unu-rmap(1) (string)
- -i <nin> , --input <nin>
input nrrd
- -o <nout> , --output <nout>
output nrrd (string); default: “-”