Posted by
Michael Schmid on
URL: http://imagej.273.s1.nabble.com/Problems-with-file-size-after-opening-GIF-files-in-ImageJ-tp3687619p3687621.html
Hi Marsilius,
GIF files have only 256 colors (8 bits per pixel, not 24 bits like
full RGB) and they are compressed using the LZW algorithm. LZW is
very efficient if you have large areas of exactly the same color.
You can save an AVI with JPEG compression; you can set the quality in
Edit>Options>Input/Output. Lower quality will produce smaller files
but introduce more artifacts. You can also try PNG compression; this
is non-lossy and has an efficiency similar to GIF. Unfortunately,
many programs don't read PNG-encoded AVIs.
In case that a program cannot read your AVI files, you can also try
to modify the image size: Some programs cannot read AVI files it the
width or height is not an integer multiple of 4 or 8.
Michael
________________________________________________________________
On 15 Jul 2010, at 12:00, Marsilius Mues wrote:
> Dear All,
>
> I have a problem when opening GIF files in ImageJ, but maybe
> someone can give me a hint: I want to make an AVI movie from a
> series of GIF files. The file size of each GIF file (325x258
> pixels, 32 colors) is about 30 KB when checking them on my
> harddrive. However, when I open them individually or as a series in
> ImageJ, each file suddenly gets a size of 82 KB which makes the
> final AVI movie much bigger then intended. What is going on here
> and is there a way to keep the small size of only 30 KB for each
> GIF file in ImageJ?
>
> Thanks a lot for your help!
> Cheers, Marsilius