.JB2 File Extension

Bitonal image created in the Joint Bi-level Image Group 2 (JBIG2) format; stores 1-bit black and white pixels in lossy or lossless format; supports greater compression ratios than the competing CCITT Fax Group 4 compression algorithm.

JB2 are segmented into three types of regions: text, halftone images, and generic regions. This allows the JBIG2 algorithm to optimize compression for the different areas of the image.

Because of their high compression ratios, JBIG2 images are commonly used to store binary images for transmission via fax. JBIG2 files replaced the previous JBIG specification (.JBIG files).