Hi,

On Thu, 2009-07-02 at 15:43 -0400, alec wrote:

I finally installed David's Batch Processor (after months of trying to figure out how to do batches) but I'm surprised that I don't see an option for changing resolution. I'm simply trying to prepare images(lots of them) for the web. Did I miss something in Daves Batches? Or maybe someone has a link to something else that would work for me? Thanks!

Resolution (as in dots-per-inch) is irrelevant for images used on web-pages. The only thing that counts is the number of pixels.

Sven

On 07/02/2009 04:06 PM, Sven Neumann wrote:

Hi,

On Thu, 2009-07-02 at 15:43 -0400, alec wrote:

I finally installed David's Batch Processor (after months of trying to figure out how to do batches) but I'm surprised that I don't see an option for changing resolution. I'm simply trying to prepare images(lots of them) for the web. Did I miss something in Daves Batches? Or maybe someone has a link to something else that would work for me? Thanks!

Resolution (as in dots-per-inch) is irrelevant for images used on web-pages. The only thing that counts is the number of pixels.

Sven

But... resolution is important for print output ... which is something I am interested in.

So I think Alec's question still stands.

Jay

alec wrote:

Akkana Peck wrote:

[..]

Resolution (as in dots-per-inch) is irrelevant for images used on web-pages. The only thing that counts is the number of pixels.

Huh, I thought that lower resolution would make the file size smaller so web images would load faster. No?

Depends what you are *really* referring to. See http://www.scantips.com/basics01.html

Von: alec

Resolution (as in dots-per-inch) is irrelevant for images used on web-pages. The only thing that counts is the number of pixels.

Huh, I thought that lower resolution would make the file size smaller so web images would load faster. No?

Absolute resolution (aka 'image size'): yes

Relative resolution (aka 'pixels per inch'): no

See also "72 dpi myth", e.g. at http://www.scantips.com/no72dpi.html

HTH, Michael

On Wed, Jul 8, 2009 at 8:45 AM, Patrick Horgan wrote:

The truth is that Gimp displays to you using your screen resolution, so if you originally created an image at 72dpi and 216x216 pixels and another image at 4800dpi and 216x216 pixels, Gimp will display them the same.

Sort of true, see below..

While
they look the same, if you look at image properties with or set the disply units to inches in the bottom border and move around the image, you can see the difference.  One is reported as 3" across and the other as .045" across.  The resolution is used by Gimp to translate to inches and inch derived units for you.

If you go into image/resize, and only change the dpi, Gimp will report to you that the image is a different size in inches, but the pixels are not in any way changed.

Various image file types like jpg and png store resolution and Gimp does store that for you.  Devices are supposed to scale the images so that on their display resolution they will appear the same size as in the images native resolution.  Some devices/software actually do this.

Like GIMP (toggle View->Dot for Dot off). When Dot for Dot is off, GIMP displays the image at a scale matching the comparitive resolutions of the screen and the image.

  If you print
something and it comes out the wrong size, some times you can open it in Gimp, change the resolution and resave.  The only change will be in the stored resolution, the file's image data is completely unchanged, yet it will now print a different size!