Gimp - 2.4 Guía Del Usuario
GNU Image Manipulation Program
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3. After you have flattened the image, you are able to
in
for your web site.
Note
You can save your image in PNG format with the default settings, but using maximum compression. Doing this will have
no negative affects on the quality of the picture, as it would have with
You can save your image in PNG format with the default settings, but using maximum compression. Doing this will have
no negative affects on the quality of the picture, as it would have with
format. If your image is a photograph with
lots of colors, you would be better off saving it as jpeg. The main thing is to find the best tradeoff between quality and
compression. You can find more information about this topic in
compression. You can find more information about this topic in
6.2.2
Reducing the File Size Even More
If you want to reduce the size of your image a bit more, you could convert your image to Indexed mode. That means that all of
the colors will be reduced to only 256 values. Converting images with smooth color transitions or gradients to indexed mode will
often give poor results, because it will turn the smooth gradients into a series of bands. This method is also not recommended for
photographs because it will make the image look coarse and grainy.
the colors will be reduced to only 256 values. Converting images with smooth color transitions or gradients to indexed mode will
often give poor results, because it will turn the smooth gradients into a series of bands. This method is also not recommended for
photographs because it will make the image look coarse and grainy.
Figure 6.7: The indexed image
An indexed image can look a bit grainy. The left image is Wilber in its original size, the right one is zoomed in by 300 percent.
1. Use the command described in Section
to convert your RGB image to indexed mode.
2. After you have converted the image to indexed mode, you are once again able to
your image in
6.2.3
Saving Images with Transparency
There are two different approaches used by graphic file formats for supporting transparent image areas: simple binary trans-
parency and alpha transparency. Simple binary transparency is supported in
parency and alpha transparency. Simple binary transparency is supported in
format. Here, one color from the indexed color
palette is marked as the transparent color. Alpha transparency is supported in
format. Here, the transparency information is
stored in a separate channel, the
Note
There is usually no need to save images in GIF format any more, because PNG supports all the features of GIF and
offers additional features (e.g., alpha transparency). Nevertheless, this format is still used for animations.
There is usually no need to save images in GIF format any more, because PNG supports all the features of GIF and
offers additional features (e.g., alpha transparency). Nevertheless, this format is still used for animations.
1. First of all, we will use the same image as in the previous tutorials, Wilber the GIMP mascot.