RAS to RB conversion is the process of transforming an image stored in the RAS (Sun Raster) bitmap format into the RB image format. This conversion re-encodes pixel data, headers, and any embedded metadata so the image can be opened, edited, or used by software that supports RB files.
Related guides
Practical guides to help you choose formats, preserve quality, and avoid common conversion problems.
Getting EPUB files onto your Kindle used to require mandatory conversion, but Amazon has gradually added native EPUB support through Send to Kindle. This guide covers every method for reading any eBook on your Kindle, from one-click email transfers to advanced Calibre workflows, plus metadata preservation, DRM considerations, and format selection between MOBI, AZW3, and KFX.
Read guide →A comprehensive guide to EPUB, MOBI, AZW, and PDF eBook formats. Compare features, device compatibility, DRM, file sizes, and learn which format is best for your reading device in 2026.
Read guide →Drag your .RAS file from your computer or use the browse function.
Confirm .rb as the selected destination format.
Click "Convert" and download your converted .RB file once ready.
RAS files use the image/x-cmu-raster MIME type and are often uncompressed bitmap images. They are typically used in legacy UNIX systems for raw image storage. RB files use a specialized MIME type tailored to the RB format, supporting efficient compression codecs for faster processing and reduced storage. Both formats serve image-related needs but differ in compression and metadata capabilities.
The RB (.RB) format is commonly used for ebook. Understanding its characteristics can be helpful when converting to or from other formats like RAS.
While specific technical details aren't available here, RB files generally serve the purpose of storing ebook effectively within their domain.
Easily convert your RAS files to RB format using our online RAS to RB converter. Designed for efficiency and reliability, this tool supports quick file conversion without the need for software installation. Whether you need to convert images or specialized files, our converter handles the job swiftly and securely.
RAS files are generally raw image files with limited compression, often used in UNIX environments. In contrast, RB files often provide better compression and support additional features like metadata and faster loading times. While RAS is more common for raw data storage, RB is optimized for usability and sharing.
Keep individual RAS files under 50–200 MB for smooth browser-based conversions; very large bitmaps can time out in web tools.
To preserve quality, choose RB uncompressed or lossless RB compression and match the original color depth and resolution.
For large batches, use a desktop converter or command-line tool that supports streaming to avoid memory limits in web services.
Be aware that some RAS files use Sun-specific headers or unusual byte orders; if colors look swapped, try toggling endianness or color depth during conversion.
The online RAS to RB converter saved me hours of manual work.
James L.
Photographer
Simple interface and fast results, perfect for my workflow.
Elena M.
Graphic Designer
Reliable and secure conversion every time I use it.
David R.
IT Specialist
Start your free RAS to RB conversion now.
Drag your file here to to upload.
Up to 250MB
RB may not support every exotic RAS metadata block; expect some custom metadata to be dropped during conversion.