Изменение размера анимированного gif

Artisan:
Попросить меня написать такую приладу.

fatalenergy:
не уверен что gd может это.
может ImageMagick поможет?

Утилита Animate из пакета ImageMagick – как видно из названия, используется для анимации, позволяет работать с анимированными gif-файлами.

The biggest problem with resizng GIF animations is that the "-resize" operator is designed specifically to make the resulting images as close to ideal (after the resize) as possible. It does this by merging and generating lots of additional colors in the image to make it look better. The resulting images are far from ideal for saving to the limited GIF file format. With GIF's limited color table, this results in heavy Color Reductions in the resized images. For a single GIF image that is not so bad, but for a GIF animations, the default Error Correction Dithering of the reduced color set produces problems, in 'dither noise' between frames, and in turn a bad frame optimization for final file size. It is even worse when transparent colors are also being used, which is a common practice for typical GIF animations used for web pages. Transparency is also commonly used for Compression Optimization techniques, for animations that would otherwise not need it.