RB to JBIG Converter

Free RB to JBIG conversion — browser-based, fast

Drop files here. 1 GB maximum file size or Sign Up
to
Facebook Amazon Microsoft Tesla Nestle Walmart L'Oreal

Optimal Text Compression

RB to JBIG conversion produces the smallest possible monochrome image files — perfect for archiving old ebook text pages.

Any Device, Any OS

Run the RB to JBIG converter from Windows, macOS, Linux, iOS, or Android. All you need is a web browser.

Guaranteed Privacy

Your RB uploads are deleted post-processing. JBIG results are purged from Convertio servers automatically within 24 hours.

How to convert RB to JBIG

1

Select files from Computer, Google Drive, Dropbox, URL or by dragging it on the page.

2

Choose jbig or any other format you need as a result (more than 200 formats supported)

3

Let the file convert and you can download your jbig file right afterwards

About formats

RB is the native ebook format of the Rocket eBook, one of the first commercially available dedicated e-reading devices, developed by NuvoMedia and released in October 1998. Founded by Martin Eberhard and Marc Tarpenning — who later co-founded Tesla Motors — NuvoMedia designed the Rocket eBook as a handheld device with a reflective LCD screen, capable of storing approximately ten books in its internal memory. The RB format packages HTML-based content along with embedded images, metadata, and a table of contents into a single binary container optimized for the device's limited hardware. Content was purchased and downloaded through NuvoMedia's RocketLibrarian desktop software. A notable advantage of the format was its early support for bookmarking, annotation, dictionary lookups, and adjustable font sizing — features now standard on modern e-readers but revolutionary in the late 1990s. The Rocket eBook demonstrated viable commercial demand for dedicated reading devices, paving the way for subsequent platforms from Sony, Amazon, and others. NuvoMedia was acquired by Gemstar-TV Guide International in 2000, which discontinued the device line in 2003. While RB files are largely a historical curiosity today, they can be converted to modern formats using ebook management tools, and the format remains significant as a pioneering chapter in the evolution of digital reading.
Developer: NuvoMedia
Initial release: 1998
JBIG (Joint Bi-level Image experts Group) is a lossless image compression standard (ITU-T T.82) published in 1993, developed by a committee of experts drawn from the same international standards bodies that created JPEG. While the extension .jbig and .jbg refer to the same underlying compression standard, .jbig is the more explicit form commonly used in software that handles the raw JBIG-compressed datastream. The compression algorithm centers on context-dependent arithmetic coding: before encoding each pixel, the encoder examines a configurable template of 10 to 16 nearby pixels (a mix of neighbors from the current and previous lines) to determine a context — one of thousands of possible local pixel configurations. Each context maintains its own adaptive probability estimate that is continually updated as encoding proceeds, allowing the coder to exploit the statistical patterns unique to each image region. This approach handles text, line art, halftoned photographs, and mixed-content pages with a single algorithm, achieving consistently better compression than the fixed Huffman tables of Group 3 or the simpler prediction model of Group 4. A later revision, JBIG2 (T.88), added pattern matching and lossy modes for even higher compression, but the original JBIG remains widely deployed. One advantage is the algorithm's adaptiveness: unlike Group 3/4 codecs that use fixed statistical models, JBIG continuously learns the characteristics of each specific image as it encodes, providing near-optimal compression across widely varying content types. The standard is embedded in many multifunction printers and document scanners for internal image handling. JBIG files are processable by ImageMagick, jbigkit, and enterprise document imaging systems.
Initial release: 1993

Frequently Asked Questions

Why convert RB to JBIG?

RB is a dead format from the Rocket eBook era. JBIG offers superb lossless compression for black-and-white page content extraction.

What programs open JBIG files?

IrfanView, XnView, GIMP (with plugins), ImageMagick, and jbigkit command-line tools all support reading JBIG files.

How does JBIG compare to TIFF?

JBIG achieves better compression ratios than TIFF for bi-level images. It was designed specifically for fax and document imaging.

Is this a free service?

Yes — RB to JBIG conversion on Convertio is completely free. Premium plans add batch processing and extra file capacity.

Are uploaded files kept?

No. Convertio deletes uploaded RB files once conversion ends and removes JBIG output files from servers within 24 hours.

What devices work with this converter?

Any device with a modern browser — desktop, laptop, tablet, or smartphone. The conversion runs server-side.