免费在线 OTB 转 G4 转换器

This format was created by Nokia for use in its proprietary phones. A bitmap image was used to transfer image files between devices over a wireless connection. It was mainly used when exchanging multimedia text messages that support inserting pictures.

G4 is a method to compress black and white images without losing quality. It is used for fax machines and as a one of the compression types for the TIFF format. G4 treats a picture as black dots and lines on a white page (less file size will be achieved if there are less black dots and lines).