Convert hdiff to bmp Online: hdiff2bmp
You can use Tom's Editor to easily convert images from
Horizontal difference image .HDIFF to Microsoft Windows bitmap .BMP.
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.
Format created by Microsoft for their Windows and OS/2 operating systems. Images can be compressed or not.