Re: [Inkscape-user] [RE] Wanting to understand issue with transparent GIF export
On Tue, 2006-11-14 at 19:44, Black Fire wrote:
Your message isn't clear how you tried to use GIMP. Did you use it to convert at PNG made with Inkscape? If not, then try exporting your Inkscape drawing as a PNG, then use GIMP to convert it to a GIF.
I was actually just pointing out that if I did something similar with GIMP, e.g. new bitmap with transparent background, white text, that it did what I expected.
I actually did what you suggested, but I gave up after I discovered that I was really dealing with a PNG anyway (see earlier message) and that I couldn't figure out in under 20 min how to get the image converted from PNG to GIF and still keep the anti-aliasing so the text looked presentable.
I finally took the original PNG, pulled it into GIMP and added the background color as a new layer to save as a GIF. Isn't what I wanted, but the visual effect is the same as long as I don't change the colors.
ast
On Wed, 15 Nov 2006 10:33:51 +0000 "Andrew S. Townley" <atownley@...16...> wrote:
I actually did what you suggested, but I gave up after I discovered that I was really dealing with a PNG anyway (see earlier message) and that I couldn't figure out in under 20 min how to get the image converted from PNG to GIF and still keep the anti-aliasing so the text looked presentable.
Ah, that one's easy. Use "convert", part of the ImageMagick suite, eg 'convert example.png example.gif' on a command line. It definitely retains full transparency, although not partial transparency (which gif may not support anyway?), and doesn't mess with the text as far as I can tell.
Convert will do a lot of /very/ useful processing to all sorts of graphic formats, and can be used as a batch processor. It's worth reading the full list of possibilities here: http://www.imagemagick.org/script/command-line-processing.php
Mike
On Wed, 2006-11-15 at 12:44, Mike Causer wrote:
On Wed, 15 Nov 2006 10:33:51 +0000 "Andrew S. Townley" <atownley@...16...> wrote:
I actually did what you suggested, but I gave up after I discovered that I was really dealing with a PNG anyway (see earlier message) and that I couldn't figure out in under 20 min how to get the image converted from PNG to GIF and still keep the anti-aliasing so the text looked presentable.
Ah, that one's easy. Use "convert", part of the ImageMagick suite, eg 'convert example.png example.gif' on a command line. It definitely retains full transparency, although not partial transparency (which gif may not support anyway?), and doesn't mess with the text as far as I can tell.
Convert will do a lot of /very/ useful processing to all sorts of graphic formats, and can be used as a batch processor. It's worth reading the full list of possibilities here: http://www.imagemagick.org/script/command-line-processing.php
Yeah, I've been using convert for a long time, but normally for batch processing of images. I haven't used command line tools for setting transparency for years, though.
However, I did try it in addition to the GIMP, but I got exactly the same results--probably due to the "partial" transparency required for the anti-aliasing to work against an alpha-only background (white text, transparent background).
Thanks for the suggestions,
ast
On Wed, Nov 15, 2006 at 01:06:14PM +0000, Andrew S. Townley wrote:
However, I did try it in addition to the GIMP, but I got exactly the same results--probably due to the "partial" transparency required for the anti-aliasing to work against an alpha-only background (white text, transparent background).
Right. As you've already noted, GIF only supports binary transparency. So, to get things looking decent, you either hand tweak the image, or premultiply the image with a known background color. GIMP suggestion follows. If you want to only merge the background color only onto the parts of the image that are partially transparent, you can select the region using the channel dialog, paint the colors using the selection into a new layer, and go from there
Jeff
participants (3)
-
Andrew S. Townley -
Jeffrey Brent McBeth -
Mike Causer