Convert flif to hdiff Online: flif2hdiff
You can use Tom's Editor to easily convert images from
Free Lossless Image Format .FLIF to Horizontal difference image .HDIFF.
Tom's Editor is a free, online image manipulation and converter program.
Go to Tom's Editor
Free Lossless Image Format is an image format with extension FLIF.
Horizontal difference image is an image format with extension HDIFF.