EPUB to RAS Converter

Convert EPUB pages to Sun Raster images online free

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Unix-Native Format

EPUB pages rendered as Sun Raster images integrate directly into Solaris, SunOS, and legacy Unix imaging pipelines.

Cloud Conversion

All EPUB to RAS processing happens on Convertio servers — no local software or computing power required.

Secure Workflow

EPUB files are deleted immediately after conversion. RAS output files are purged from servers within 24 hours.

How to convert EPUB to RAS

1

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

2

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

3

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

About formats

EPUB (Electronic Publication) is an open ebook standard originally developed by the International Digital Publishing Forum (IDPF) and now maintained by the W3C following the organizations' merger in 2017. The first version carrying the EPUB name was approved in October 2007 as a successor to the Open eBook Publication Structure (OEBPS). An EPUB file is essentially a ZIP archive containing XHTML or HTML5 content documents, CSS stylesheets, images, fonts, and metadata organized according to the Open Packaging Format and Open Container Format specifications. The current major version, EPUB 3, supports reflowable and fixed-layout content, embedded multimedia, JavaScript interactivity, MathML equations, and rich accessibility features including semantic markup and media overlays for synchronized text and audio. A defining advantage is universal device support — unlike proprietary formats, EPUB works natively on virtually every non-Kindle e-reader, tablet, and reading application, from Apple Books and Google Play Books to Kobo and dozens of third-party apps. The reflowable text model is another core strength, automatically adapting pagination, font size, and margins to match any screen dimension and user preference. EPUB's open specification and active W3C stewardship ensure long-term preservation and vendor independence, making it the de facto standard for digital publishing across libraries, academic institutions, and commercial retailers worldwide.
Initial release: October 2007
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

Frequently Asked Questions

Why convert EPUB to RAS?

Sun Raster is a native image format for Solaris and SunOS — needed when integrating ebook page renders into legacy Sun/Unix imaging workflows.

What software opens RAS files?

ImageMagick, GIMP, XnView, and Sun/Oracle Solaris native image tools all support the Sun Raster format.

Can RAS handle color images?

Yes — RAS supports 1-bit, 8-bit, and 24-bit color depths, so EPUB pages convert with full color fidelity.

Does each EPUB page become a separate file?

Each page is rendered individually as its own RAS image file, preserving the original reading order of the ebook.

Is EPUB to RAS free?

Yes, Convertio offers this conversion free of charge. Premium accounts provide higher throughput for batch conversions.