RGF to SNB Converter

Export RGF images as SNB documents — free

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One-Click Retrieval

Download your SNB result as soon as the conversion ends. The output stays available for a full day if you need to grab it later.

Quick Turnaround

The converter processes RGF images rapidly. Most RGF to SNB conversions finish within moments of starting.

Private and Secure

Your RGF files are deleted right after conversion, and SNB outputs are erased within 24 hours. Your data remains entirely confidential.

How to convert RGF to SNB

1

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

2

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

3

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

About formats

RGF (Robot Graphics Format) is a simple monochrome bitmap image format used by LEGO Mindstorms EV3 programmable robotics kits, introduced with the EV3 system on September 1, 2013. RGF files store 1-bit (black and white) images designed for display on the EV3 Intelligent Brick's 178x128 pixel monochrome LCD screen. The format uses a minimal structure: a header containing the image width and height as binary values, followed by the pixel data where each bit represents one pixel (1 for black, 0 for white), packed eight per byte in row-major order. RGF images are used as custom display graphics in EV3 programs — students and hobbyists create them for robot status displays, user interfaces, splash screens, and animation frames shown on the brick's screen during program execution. The images are typically designed using LEGO's EV3 software (which includes a built-in image editor) or converted from other formats using community tools. RGF fits within LEGO's broader educational robotics platform, where the Mindstorms system teaches programming, engineering, and computational thinking to students worldwide. One advantage is the format's role in educational technology: RGF provides a simple, concrete example of how digital images are represented as binary data — a concept that students working with Mindstorms can directly observe by examining the file contents and seeing the corresponding image on the brick's screen. The format's simplicity makes it accessible for young programmers learning about file formats and binary data. RGF files can be created and converted using ImageMagick, the EV3 development environment, and community tools like ev3dev.
Developer: The LEGO Group
Initial release: 2013
SNB is a proprietary ebook format developed by Shanghai Nutshell Electronics, a subsidiary of Shanda Interactive Entertainment, for the Bambook e-reader launched in August 2010. The format is structurally based on EPUB principles, packaging HTML content, CSS styling, images, and metadata within a compressed archive, but uses a proprietary container that restricts native playback to Bambook devices and associated software. Shanda designed the Bambook and its SNB ecosystem as an integrated reading platform tied to the Cloudary literature portal (later rebranded as China Literature), one of China's largest online publishing networks hosting millions of web novels and serialized fiction. The format supported reflowable text, chapter navigation, bookmarks, and basic typographic controls suited to Chinese-language content display. One advantage was tight integration with Shanda's massive content catalog, providing readers instant access to an enormous library of Chinese-language literature directly through the device. The Bambook was initially offered at a heavily subsidized price point, using the content ecosystem to drive revenue — a model that preceded similar strategies by other e-reader manufacturers. While the Bambook hardware line was eventually discontinued as the Chinese market shifted toward tablet-based reading apps, SNB files from that era can be converted to standard formats using tools like Calibre with appropriate plugins. The format represents an interesting case study in platform-specific ebook ecosystems within the Chinese digital publishing landscape.
Initial release: August 2010

Frequently Asked Questions

Why convert RGF to SNB?

Placing RGF images into SNB format lets recipients view them in standard document readers — far more accessible than raw RGF files.

What programs open SNB files?

Standard document viewers handle SNB files — Microsoft Office, LibreOffice, Adobe Reader, or Calibre for e-book formats.

What makes RGF files distinctive?

RGF images are extremely small monochrome graphics — designed to fit on a tiny LEGO robot LCD screen. They represent a unique niche in imaging.

How is image quality handled during conversion?

The converter extracts full image data from RGF and encodes it into SNB at the highest quality the target format allows. No unnecessary loss.

Do I need to install anything?

No installation needed — the conversion happens entirely online. Open the converter in any modern web browser and your device handles the rest.