SUN to DocBook Converter
FileFlip converts SUN to DocBook entirely inside your browser, using ImageMagick, MuPDF and Pandoc compiled to WebAssembly. The file is never uploaded to a server: it is read off your disk, converted on your own machine, and saved back by the browser. That means no file-size limit, no queue and no account.
How do I convert a SUN file to DocBook?#
- Drop your SUN file onto the converter at the top of this page, or click it to pick one from your computer. You can add as many as you like.
- Leave the target set to DocBook and the conversion starts on its own. FileFlip downloads 79.9 MB of WebAssembly the first time and nothing after that, then runs ImageMagick, MuPDF and Pandoc on your own machine.
- Save the DocBook file. Your browser writes it straight to your downloads folder, because there was never a server holding it.
Does converting SUN to DocBook lose quality?#
No. The SUN picture is placed into the DocBook document at its full resolution, so every pixel reaches it intact. What you give up is that it becomes a picture inside a document rather than text.
Is it safe to convert SUN files online?#
Yes, because nothing is uploaded. FileFlip converts SUN files inside the browser tab you already have open, using WebAssembly builds of the same engines a desktop converter would install. Your file is read from your own disk into the page's memory, and no request carrying it is ever made.
You do not have to take that on trust. Open your browser's network panel, run a conversion, and you will see the engine come down and your file go nowhere. There is no upload, no server-side copy, no retention window, and no account tied to what you converted.
How FileFlip works lists every engine, its version and its download size, and shows how to check for yourself that nothing leaves your machine.
What SUN to DocBook actually does to the file#
Converting SUN to DocBook runs on ImageMagick, MuPDF and Pandoc, downloads 79.9 MB of WebAssembly the first time and nothing after that, places the picture into the document at full resolution.
| Engine | ImageMagick, MuPDF and Pandoc |
|---|---|
| Conversion path | 3 steps: SUN → PNG → HTML → DocBook |
| Downloaded to your browser | 79.9 MB, once, then cached by your browser |
| Quality | Pixels preserved |
| You get back | One file |
| Where it runs | In a background worker, so the page stays responsive |
Worth knowing before you start:
- the picture is placed in the document as a picture; no text is recognised out of it
- the file passes through HTML on the way, so anything HTML cannot express does not survive
What is a SUN file?#
A SUN file is a Sun Raster bitmap, the same raw framebuffer image format Sun Microsystems shipped on SunOS workstations, saved under the alternate .sun extension some raster-image tools use in place of the identical .ras.
Recognise a .sun file as a Sun Raster image if it turns up alongside .ras files from the same legacy Solaris export or archive.
Convert SUN to PNG or TIFF for any modern use, since the .sun extension gets even less software recognition than .ras.
What is a DocBook file?#
A DBK file is a DocBook document, XML markup that describes a technical document's structure and meaning, such as chapters, sections, and code listings, rather than its visual layout, so one source can be styled into a printed book or a web page.
Write in DocBook when producing technical documentation that has to publish to multiple outputs, such as print, web, and help, from one validated source.
Convert DocBook to another format when the reader only needs the finished document and doesn't need to maintain the structured XML source.
SUN to DocBook questions people ask#
What is a SUN file?
A SUN file is a Sun Raster bitmap, the simple framebuffer image format Sun Microsystems used on SunOS and Solaris workstations, identified by a fixed magic number at the start of the file rather than by its extension.
Is SUN the same format as RAS?
Yes, a SUN file and a RAS file are the identical Sun Raster format. The two extensions exist because different tools over the years registered the format under different names, not because the files differ in any way.
Can I just rename a .sun file to .ras?
Renaming a .sun file to .ras works, because the two extensions point at the same byte-for-byte format and most decoders identify a Sun Raster file by its magic number rather than its extension. Some tools that only recognise .ras will open the renamed file without issue.
What opens a .dbk file?
A .dbk file is DocBook XML, which is plain text, so any text or XML editor opens it, though tools like Oxygen XML Editor or Visual Studio Code with an XML extension add validation and structure awareness. Converting it to HTML or PDF is the usual way to read it as a finished document.