JB2 File – What is .jb2 file and how to open it?

Definition of a JB2 File

A JB2 file is a raster image file using the JBIG2 compression standard developed by the Joint Bi-level Image Group (JBIG). JBIG2 is a lossless compression algorithm specifically designed for high-quality bi-level (black-and-white) images. It offers higher compression ratios and better image quality compared to previous JBIG versions and other comparable compression techniques.

Applications of JB2 Files

JB2 files are commonly used in the following applications:

• Document Imaging: JB2 compression is widely adopted in the document imaging industry for scanning and storing high-volume black-and-white documents, such as invoices, contracts, and legal files. It reduces file sizes significantly while preserving image quality, making them suitable for long-term archiving and secure document sharing.
• Fax Communication: JB2 is the standard image compression format used in fax machines. It ensures fast and reliable transmission of bi-level images over telecommunication lines, reducing transmission time and minimizing file sizes.
• Medical Imaging: JB2 is employed in the medical field, particularly for the storage and transmission of bi-level medical images, such as X-rays and mammograms. Its high compression ratios and preservation of image quality facilitate efficient data management and remote image sharing for medical diagnostics.

JBIG2 Image File Format

JBIG2 (Joint Bi-Level Image Group 2) is a compressed image file format specifically designed for bi-level (black-and-white) images. It is an improved version of the earlier JBIG format, offering higher compression ratios and improved image quality. JBIG2 is widely used in applications such as document scanning, fax transmission, and electronic book readers.

To open a JB2 file, you will need a software program that supports the JBIG2 file format. Several popular image viewers and document management systems can open JB2 files. Some examples include:

• ImageMagick (open-source software for image processing)
• GIMP (open-source image editing software)
• XnView (image viewer and converter)
• Adobe Acrobat Reader (for viewing PDF documents that contain JB2 images)

Opening JB2 Files in Specific Applications

• ImageMagick: Open a terminal window or command prompt and navigate to the directory containing the JB2 file. Enter the following command, replacing “image.jb2” with the actual file name:


convert image.jb2 image.png


This command will convert the JB2 file to a PNG image, which can be opened by most image viewers.

• GIMP: Open GIMP and go to “File” > “Open” to browse for the JB2 file. Once the file is opened, you can edit or save it in another image format.

• XnView: Open XnView and drag and drop the JB2 file into the application window. XnView will automatically load the image and allow you to view and convert it to other formats.

JB2 File Format

JB2 files are commonly associated with images compressed using the JBIG2 compression algorithm, developed by the Joint Bi-level Image Group (JBIG). This compression method is specifically designed for black-and-white (bi-level) images, such as scanned documents, fax transmissions, and medical images. JBIG2 offers efficient compression without sacrificing image quality, making it suitable for applications where file size reduction is critical.

JB2 Properties

The JBIG2 encoder employs a combination of techniques, including bi-level arithmetic coding, context-based modeling, and adaptive templates, to achieve high compression ratios. JB2 images typically achieve compression ratios of 10:1 to 20:1, significantly reducing the file size compared to uncompressed formats. Additionally, JBIG2 supports multiple resolutions and regions of interest, allowing for efficient transmission and selective decoding of specific image areas.

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