On 22 September 2013 05:57, Juan Nunez-Iglesias <jni.soma@gmail.com> wrote:

On Sun, Sep 22, 2013 at 1:20 PM, Jaime Fernández del Río < jaime.frio@gmail.com> wrote:

...

So a pixel replicated TIFF image has twice the resolution, as per the above official definition, not the same resolution with twice the sampling.

Even in this case, what we call sampling/spacing is the *inverse* of that definition of resolution.

I think strictly speaking, the term "resolution" is a measure for visibility of detail. The term is used a lot to simply denote the *number* of pixels, e.g. 800x600, 1024x768, etc. Spacing/sampling is really just a a measure (usually in mm) that specifies the distance between two pixels. If you know the number of pixels, and the sampling, you know the image size in physical units. - Almar