[[xEsk]]

Código Delphi [-]
  h := img.Height;
  w := img.Width;

Devuelve las medidas en píxeles, como te dije en el otro mensaje...

Y como dice la ayuda del delphi:

TPicture.Height Property
Specifies the vertical size (in pixels) of the graphic.
Description
Use Height to find the height of the graphic image contained in the picture object. Height is the native, unstretched, height of the picture.

TPicture.Width Property
Specifies the horizontal size (in pixels) of the picture.
Description
Use Width to find the width of a graphic image. Width contains the native, unstretched, width of the picture.