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

[Moritz Lennert]

On 17/11/13 23:13, Nick Ves wrote:
> The HPF algorithm about the histrogram matching states "Stretch the
> new multispectral image to match the mean and standard deviation of
> the
> original (input) multispectral image"
>
> In that context why it is wrong to do  :
>
> Ouput <- output/sddev(output)*sddev(input)
>
> Output <- Output - mean(output) + mean(input)
>

To give the 'new' image the same mean and stddev of the 'input' image:

(new - mean(new)) / stddev(new) * stddev(input) + mean(input)

Moritz