2007.12.09 18:54 "Re: [Tiff] dpi settings", by Toby Thain
On 9-Dec-07, at 4:39 PM, Andrey Kiselev wrote:
On Sun, Dec 09, 2007 at 11:15:51AM -0600, Bob Friesenhahn wrote:
For me centimeter unit is quite inconvenient for the image processing related usage. I like mm.
It seems that the best unit to use depends on what is being measured and the intent of the measurement.
That is very true. And we are talking here about resolution tags which intended to set up the relation between image pixels and actual size of paper sheet or display. And millimeters are quite convinent in measuring of paper sheets and displays.
Centimetres also, see previous. Furthermore it does appear to be established convention in pre-press (my old métier).
For example, if the TIFF file represents a satellite image covering a large expanse of the earth, and it is desired to specify the actual resolution, units of millimeters would be inconvenient. Perhaps meters or kilometers would be more convenient. If an image is from a microscope, perhaps nanometers or micrometers would be more convienient.
Oh, no, you are just mesunderstanding the resulution tags purpose. They have nothing to do with the actual image content. The same 300 dpi image can be the view of the whole Earth from space or just a bacteria photograph, but it still remains the 300 dpi image. The scale of the image content should be established via anther tags.
> Tiff mailing list: Tiff@lists.maptools.org