Image manipulationwith GIMP and convert

[Robin Laing]

Artur G. Sibagatullin wrote:
> Hello everybody!
> In order to convert large amount of pictures I need a command-line
> script which use convert command.
> Thats why I got a question.
> When I used GIMP, I did the following: reduce resolution of the picture
> while number of pixel remain the same, at the expense of this the size
> of the picture in inches get larger. After that by reducing the size in
> inches I increased the resolution as high as it possible. As the result
> I had smaller picture with quiet high resolution. How must I do that
> using convert command?
> Thanks!
> 

Image resolution is confusing in that there are different resolutions to 
work with.  Screen resolution is set at one level.  Print resolution is 
set at another level.  What resolution were you changing?

Of course if you just changed the screen resolution, then you didn't 
really change the image resolution.  I don't think that you can use 
convert to change the screen resolution.

The question comes down to why would you want to change the pixel per 
inch for files that don't change size?  This can be done on the fly with 
most viewers or print programs.

-- 
Robin Laing