Re: [Gimp-user] Scaling an image down without ruining the text

[Liam R E Quin <liam holoweb net>]

On Thu, 2017-06-15 at 11:01 +0200, CC4581 wrote:
> Hi,
>
> I have an image that is currently 2590 x 344. It is a footer image to
> be used in auto generated letters for a bespoke CRM system that is
> currently being developed. The required dimensions for the image are
> 790 x 115.

Then develop the CRM system to support SVG vector images, or to be able
to add text to an image on the fly (e.g. see the gd library).


> Unfortunately, when I scale the image down to these dimensions,

As others pointed out, you can't scale down 2590x344 to get to 790x115
without adding distortion.

Make your larger image be a whole-number multiple of your target size -
ideally a power of two larger (2, 4, 8, 16...). It will scale don a LOT
better. For example, 3160 x 460 pixels (4 * 790, 4 * 115). If there was
a typo in your mail and you didn't mean 790x115, use 4 times the size
you meant :-)

Then use tool options to try the various different scaling algorithms
to see which is best. For Gimp 2.8 I'd likely do
(1) flatten the image
(2) gaussian blur 3x3
(3) scale down with "cubic" or "lancsoz" (experiment to compare)
(4) filters->enhance->sharpen (in 2.8 this is better than unsharp mask,
or I found it so, for this application).

For gimp 2.8 try without doing the blur first, and then try unsharp
mask after.

Then export, then undo to get back to having multiple layers.

You could also add the text later. For www.fromoldbooks.org I add the
text to the images using ImageMagick.

Liam


-- 
Liam R E Quin <liam holoweb net>

Web slave for fromoldbooks.org