Convert bmp to otb Online: bmp2otb
You can use Tom's Editor to easily convert images from
Microsoft Windows bitmap .BMP to On-the-air Bitmap .OTB.
Tom's Editor is a free, online image manipulation and converter program.
Go to Tom's Editor
BMP
Format created by Microsoft for their Windows and OS/2 operating systems. Images can be compressed or not.
OTB
On-the-air Bitmap is an image format with extension OTB.