A gif output is always larger?

[28QiGkMfTYDN3dP9tn1S]

There is a gif file, when I input it in GIMP and output it as another gif, it is always obviously larger than the input gif. Why? I tried some methods to optimize it.

Sorry I am not able to add an attachment.

[rich2005]

If you can not share the file then look at the before-after properties.

If it is an animation, the number of layers (frames)
Does the new gif have transparency.
If the old file is optimised and you un-optimised for editing Maybe re-optimising not as efficient.

The one thing that can get larger is the color map. How many colors does the original have compared with the new file. Open the colormap dock Windows -> Dockable Dialogs -> Colormap

[28QiGkMfTYDN3dP9tn1S]

(11-20-2022, 08:28 AM)rich2005 Wrote: If you can not share the file then look at the before-after properties.

If it is an animation, the number of layers (frames)
Does the new gif have transparency.
If the old file is optimised and you un-optimised for editing Maybe re-optimising not as efficient.

The one thing that can get larger is the color map. How many colors does the original have compared with the new file. Open the colormap dock Windows -> Dockable Dialogs -> Colormap

It is an animation. It has no transparency in visual. It contains 75 frames and 254 colors. After dealing, it is lossless, still original frames and colors. 

Original file: 2.6MiB.
Outputing directly: 3.2MiB.
Un-optimesing selection: 3.8MiB.
Optimizing for gif selection: 4.1MiB.
Optimizing selection: 4.3MiB.


I heard gif is a complex format. Now it seems indeed.