[GRASS-dev] Implementation of the High Pass Filter Additive Fusion technique (i.fusion.hpf)

[Markus Neteler]

On Sat, Nov 16, 2013 at 9:27 PM, Michael Barton <Michael.Barton at asu.edu> wrote:
> I took a look at the i.pansharpen code. The method matchhist does the histogram matching. It creates cumulative distribution functions (CDF) of the source and target histograms and then finds the closest values to match at each point on the CDF. It is pretty thoroughly documented in the code. There are other methods of histogram matching, but IIRC, this was the most basic and widespread. As some others have commented, it assumes that images have 256 integer grey values. A more sophisticated histogram matching algorithm could utilize floating point values and a wider range of values. Hope this helps

How does it compare to the one used in the Addon "i.hist.match"?
(grass-addons/grass7/imagery/i.histo.match/i.histo.match.py)

There I don't see a 8bit limitation (I may be wrong). This might solve
ticket #2048.

Markus