Convert hdiff to flif Online: hdiff2flif
You can use Tom's Editor to easily convert images from
Horizontal difference image .HDIFF to Free Lossless Image Format .FLIF.
Tom's Editor is a free, online image manipulation and converter program.
Go to Tom's Editor
Horizontal difference image is an image format with extension HDIFF.
Free Lossless Image Format is an image format with extension FLIF.