RAS to RB Converter

Turn RAS into RB ebooks online for free

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

Accurate Conversion

Convertio faithfully translates your RAS pixel data into a properly structured RB result — preserving visual content throughout.

Visual Fidelity

The RAS to RB conversion retains your image content faithfully — colors, details, and dimensions come through intact.

Simple Workflow

Three steps: upload RAS data, pick RB, download the result. No technical knowledge required — Convertio handles everything.

How to convert RAS to RB

1

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

2

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

3

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

About formats

RAS (Sun Raster) is a raster image format developed by Sun Microsystems for their SunOS and Solaris Unix workstations, dating to approximately 1982. Sun Raster files store 2D bitmap images with support for 1-bit monochrome, 8-bit indexed color (with a color map), 24-bit true color (BGR byte order), and 32-bit XBGR (with an unused alpha byte). The format uses a 32-byte header containing a magic number (0x59a66a95), width, height, bit depth, data length, raster type (indicating compression), color map type, and color map length, followed by the optional color map data and the pixel data. RAS supports three encoding modes: standard (uncompressed, with each scanline padded to a 16-bit boundary), byte-encoded (run-length encoded using a simple escape-code scheme), and RGB (uncompressed with RGB rather than BGR byte order). Sun Raster was the native image format for Sun's window system and later the OpenWindows desktop environment, serving as the standard format for screenshots, icons, backgrounds, and application graphics on Sun workstations throughout the 1980s and 1990s. One advantage is the format's representation of Unix workstation computing heritage: Sun Raster files from the SunOS/Solaris era document the visual culture of an important computing platform that drove advances in networking, multiprocessing, and graphics workstation design. The format's straightforward structure is another practical strength — the 32-byte header and simple encoding make RAS files easy to parse and convert, even with custom code. RAS files are supported by ImageMagick, GIMP, XnView, and other image processing tools.
Developer: Sun Microsystems
Initial release: 1982
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

Frequently Asked Questions

Why convert RAS to RB?

RAS was designed for Sun workstations and is obsolete today. RB conversion ensures your image works across all modern platforms.

What programs open RB files?

RB files can be opened in Rocket eBook devices, Calibre, and legacy ebook reader applications.

What platforms support this converter?

Convertio runs in any modern web browser — Chrome, Firefox, Safari, Edge — on Windows, macOS, Linux, Android, and iOS devices.

Does the converter handle batch RAS uploads?

Absolutely. You can upload multiple RAS sources simultaneously and convert all of them to RB in one go — no need to repeat the process.

Why choose RB format?

RB offers legacy ebook format, early e-reader standard. Converting RAS content into RB makes it ready for e-readers and digital distribution.