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5.4 Histogram

This menu groups operations for finding and transforming image histograms. `nip2` represents histograms and lookup tables as images with `Type` set to `Histogram`. Histograms may have pixels in any format and any number of bands. You can only find histograms of unsigned 8- and 16-bit images.

`New Histogram`
  This makes a new ramp histogram. A set of sliders let you adjust the shape. Use `Map Histogram` to apply your ramp to an image.

`Find Histogram`
  A one dimensional histogram treats each band as an independent variable. An -dimensional histogram treats each pixel as a vector of elements, where is the number of bands in the image.

`Map Histogram`
  Looks up each pixel in the input in the histogram and send the found value to the output.

`Histogram Equalisation`
  Find the global or locally histogram equalised image.

`Cumulative Histogram`
  Use this and friends to calculate a cumulative histogram, normalise a histogram and match two histograms.

`Find Profile`
  Searches from the edges of an image for the first non-zero pixel and returns a profile histogram.

  Mark a guide on an image (drag from the image rulers, or click `File` / `New` / `Guide`) and click `Slice Image` to make a histogram which is a horizontal or vertical slice through an image.

Next: 5.5 Image Up: 5. Image processing menus Previous: 5.3 Format Contents