Plotting grey scale images.

Hello ,

I am trying to plot grey scale images of size 631 x 661 having negative values ranging from -21.35 to -13.26.After reading the image ,it shows black pixels unless [] are given.I want to plot geoshow command.How can i do it. I tried geoshow command but it gives images of black pixels ..

I=imread('GBGEO.tif') ;

VV=I(:,:,2);

imshow(VV,[]).

geoshow(lat,long,VV)

[Rik]

Most function will assume images of type double have a data range of [0 1], unless you tell them otherwise. The documentation for geoshow is a bit unclear about this, but it seems to follow the same convention.

You should rescale your data to whatever you're expecting to be the data range. Using [] with imshow implicitly rescales your data to [0 1], so like this:

data=(data-min(data(:)))/(max(data(:))-min(data(:)));

(actually it sets the caxis instead of changing your data)