免费在线 G4 转 PNM 转换器

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).

A bitmap image in the Portable Any Map format that was originally developed for processing and storing several types of monochrome and color images without compression as well as grayscale images. Bitmap graphics data in a PNM file are stored using ASCII or binary structure.