ERF to RGF Converter

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.