How to know the length of the lossless compressed file?

[yuffon]

Now I have a number of images stored in numpy file.
I want to use FLIF to compress them losslessly and count the length?
Does this library provide API to count the length directly?

[bjorn3]

#554

FLIF development has stopped since FLIF is superceded by FUIF and then again by JPEG XL (https://jpeg.org/jpegxl/index.html), which is based on a combination of Pik and FUIF.
A royalty-free and open source reference implementation of JPEG XL is available on GitLab.

[yuffon]

#554

FLIF development has stopped since FLIF is superceded by FUIF and then again by JPEG XL (https://jpeg.org/jpegxl/index.html), which is based on a combination of Pik and FUIF.
A royalty-free and open source reference implementation of JPEG XL is available on GitLab.

Thank you for your reply.
I am investigating a project. In this project, the author uses FLIF to compress files.
I want to know the length of the compressed file.
I see that the flif file format contains several headers in front of the file.
So I want to know the length of the rest part.

[bjorn3]

I am not familiar enough with the actual file format to help you with this.