SUN to G4 Converter

Transform SUN into G4 images quickly online

Drop files here. 1 GB maximum file size or Sign Up
to
Facebook Amazon Microsoft Tesla Nestle Walmart L'Oreal

Works Everywhere

Desktop, tablet, or phone — the converter runs on any device with a web browser. No platform restrictions for SUN to G4 conversion.

Batch Uploads

Queue multiple SUN inputs and convert them all to G4 in one session. Batch processing saves time when you have many files to handle.

Reliable Output

SUN data is accurately transformed into well-formed G4 output. The conversion engine handles the format differences automatically.

How to convert SUN to G4

1

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

2

Choose g4 or any other format you need as a result (more than 200 formats supported)

3

Let the file convert and you can download your g4 file right afterwards

About formats

SUN is a raster image format associated with Sun Microsystems workstations, encompassing both the Sun Raster format (.ras) and the Sun Icon format used for window system icons and cursors on SunOS and Solaris systems. Sun Raster files, identifiable by their 0x59a66a95 magic number, store bitmap images in 1-bit monochrome, 8-bit indexed color, 24-bit BGR, or 32-bit XBGR modes, with optional run-length encoding compression and a 32-byte header. The Sun Icon subset is a simpler text-based format used for small monochrome bitmaps — window icons, cursor images, and toolbar graphics — stored as C-language data arrays that could be directly compiled into X Window and SunView applications. These icon files begin with a comment block specifying width, height, and optionally hot spot coordinates (for cursor images), followed by hexadecimal pixel values in a format readable by both the C compiler and the iconedit tool. Sun workstations running SunOS and later Solaris were foundational platforms for Unix computing, networking, and the early internet, and the SUN image formats were integral to their graphical environments. One advantage is the format's dual text/binary nature: Sun Icons are valid C source code that can be #included directly into applications, a practical approach to resource embedding that predates modern asset management systems. The Sun Raster variant's simplicity provides another strength — the 32-byte header and straightforward encoding make it one of the easiest binary image formats to parse. SUN format files are supported by ImageMagick, GIMP, XnView, and Unix image viewing tools.
Developer: Sun Microsystems
Initial release: 1982
G4 is a monochrome image format based on the ITU-T Group 4 facsimile coding standard (Recommendation T.6), ratified by the CCITT in 1984 as an improvement over Group 3 for use on error-free digital networks like ISDN rather than analog telephone lines. G4 files contain 1-bit image data compressed using exclusively two-dimensional Modified Modified READ (MMR) coding, where each scanline is encoded as a set of differences (changing elements) relative to the line above it. By eliminating the one-dimensional coding fallback and the end-of-line synchronization markers required by Group 3, G4 achieves 20-50% better compression ratios on typical document pages while producing a simpler, more regular bitstream. The format is most commonly encountered as a compression method within TIFF files (TIFF compression tag 4), where it became the standard archival format for scanned documents in enterprise document management, government records, and legal imaging systems. G4 compression is specified at 200, 300, or 400 dpi depending on the scanning application, with 300 dpi being the most common for archival-quality document imaging. One advantage is exceptional compression efficiency for document content: G4's two-dimensional prediction exploits the strong vertical correlation in text and line art pages, typically compressing a 300 dpi letter-size page to 30-50 KB — roughly half the size of equivalent Group 3 encoding. The format's entrenchment in document management infrastructure is another strength — G4 TIFF is the mandated format for many government digital records systems, court filing systems, and corporate archives, supported by every enterprise imaging platform.
Developer: ITU-T (CCITT)
Initial release: 1984

Frequently Asked Questions

Why convert SUN to G4?

SUN was built for Sun Microsystems hardware that is long discontinued. G4 offers the broad compatibility modern workflows demand.

What programs open G4 files?

G4 files can be opened in fax viewers, IrfanView, XnView, and document management software.

Does this work on Mac and Linux?

Convertio is entirely browser-based, so it works on macOS, Linux, Windows, and even mobile platforms without any software installation.

Is SUN to G4 conversion lossless?

The pixel data from your SUN source is mapped faithfully to G4. Whether the result is lossless depends on the G4 format's compression method.

How does Convertio protect my uploaded data?

Your SUN data is encrypted during transfer and deleted after processing. Converted G4 outputs are purged from servers within 24 hours.