SUN to RB Converter

Convert SUN images to RB ebook format online

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Simple Workflow

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

Secure Handling

All SUN uploads are deleted upon conversion, and RB output files are scrubbed from servers within 24 hours — your privacy is non-negotiable.

Cloud Conversion

All processing runs on remote servers — no local resources consumed. Upload your SUN data and let the cloud deliver your RB output.

How to convert SUN 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

SUN is a raster image format associated with Sun Microsystems workstations, encompassing both the Sun Raster format (.ras) and the Sun Icon format used for window system icons and cursors on SunOS and Solaris systems. Sun Raster files, identifiable by their 0x59a66a95 magic number, store bitmap images in 1-bit monochrome, 8-bit indexed color, 24-bit BGR, or 32-bit XBGR modes, with optional run-length encoding compression and a 32-byte header. The Sun Icon subset is a simpler text-based format used for small monochrome bitmaps — window icons, cursor images, and toolbar graphics — stored as C-language data arrays that could be directly compiled into X Window and SunView applications. These icon files begin with a comment block specifying width, height, and optionally hot spot coordinates (for cursor images), followed by hexadecimal pixel values in a format readable by both the C compiler and the iconedit tool. Sun workstations running SunOS and later Solaris were foundational platforms for Unix computing, networking, and the early internet, and the SUN image formats were integral to their graphical environments. One advantage is the format's dual text/binary nature: Sun Icons are valid C source code that can be #included directly into applications, a practical approach to resource embedding that predates modern asset management systems. The Sun Raster variant's simplicity provides another strength — the 32-byte header and straightforward encoding make it one of the easiest binary image formats to parse. SUN format files are supported by ImageMagick, GIMP, XnView, and Unix image viewing 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 SUN to RB?

Very few modern applications recognize SUN files. RB conversion ensures your image works seamlessly on any platform or device.

What programs open RB files?

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

Why choose RB format?

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

Is my SUN data safe during conversion?

Yes — uploaded data is processed securely and deleted immediately after conversion. Output files are removed from servers within 24 hours.

What platforms support this converter?

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