how i can get the dpi of a image?
First you need the current sources from SVN repository.
Then you can use this code:
var
XRes, YRes: Single;
begin
... load image
if GlobalMetadata.GetPhysicalPixelSize(ruDpi, XRes, YRes) then
... do something with DPI info
If GetPhysicalPixelSize returns False that means no DPI info was present in the last loaded image. Also note that currently DPI info is read only from JPEG, PNG, and TIFF images.