G3 to VIFF Converter

Digitize G3 files to VIFF — free online converter

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Secure Processing

Source G3 files are deleted instantly after conversion. VIFF output files are auto-removed within 24 hours.

Multiple Files

Process several G3 files in a single session. Each produces a separate VIFF file for individual download.

Fax Preservation

Preserve fax content by converting G3 to widely supported VIFF — future-proof your document archive.

How to convert G3 to VIFF

1

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

2

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

3

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

About formats

G3 is a monochrome image format based on the ITU-T Group 3 facsimile coding standard (Recommendation T.4), ratified by the CCITT in 1980 as the universal compression method for fax transmission over telephone networks. G3 files contain 1-bit (black and white) image data encoded using Modified Huffman (MH) one-dimensional coding, where each scanline is independently compressed by replacing runs of consecutive white or black pixels with variable-length codewords from a predefined Huffman table optimized for typical document content. The standard also defines an optional two-dimensional coding mode (Modified READ) that encodes each line as differences from the previous line, achieving better compression for pages with vertical redundancy. Standard G3 resolution is 204 pixels per inch horizontally and either 98 (standard) or 196 (fine) pixels per inch vertically, producing the characteristic slightly-stretched appearance of received fax documents. The encoding was carefully optimized for the real-time transmission constraints of 1980s modems operating at 2400 to 14400 bps, where encoding and decoding speed had to match the communication channel rate. One advantage is universal telecommunications compatibility: Group 3 encoding remains the mandatory baseline codec for every fax machine manufactured, ensuring that G3 image data can be transmitted to or received from any fax device worldwide. The format's efficiency for document content is another strength — the Huffman tables were statistically tuned to the run-length distributions found in business documents, and typical pages compress to under 30 KB. G3 files are supported by LibreOffice, ImageMagick, and fax server software.
Developer: ITU-T (CCITT)
Initial release: 1980
VIFF (Visualization Image File Format) is a scientific image format developed by Khoral Research (originally at the University of New Mexico), first appearing around 1990 with the Khoros visual programming environment for image processing and data visualization. VIFF files use a 1024-byte header followed by optional color map data, and the image data itself, with the header containing detailed specifications: data storage type (bit, byte, short, integer, float, double, complex), data encoding (none, CCITT Group 3/4), color space model (none, generic, RGB, HSI, CMYK, and others), and support for multi-band (multi-channel) images with arbitrary numbers of bands. The format accommodates one-dimensional signals, two-dimensional images, three-dimensional volumes, and location data (sparse pixel coordinates), making it versatile beyond simple image storage. VIFF was designed for the Khoros/VisiQuest visual dataflow programming environment, where users constructed image processing pipelines by connecting processing nodes in a graphical canvas — an approach that influenced later systems like AVS, MATLAB Simulink, and LabVIEW. One advantage is scientific data fidelity: VIFF supports the full range of numeric types used in scientific computing (including complex numbers and double-precision floats), stores multi-band datasets natively, and carries calibration metadata — making it suitable for remote sensing, medical imaging, and spectral analysis applications where generic image formats lose information. The format's connection to the Khoros visual programming paradigm provides another notable dimension — VIFF was the standard I/O format for one of the most influential early visual programming environments for scientific image analysis. VIFF files can be read by ImageMagick and legacy Khoros/VisiQuest installations.
Developer: Khoral Research
Initial release: 1990

Frequently Asked Questions

Why convert G3 to VIFF?

VIFF is widely supported by image viewers and browsers — converting from G3 eliminates the need for fax tools.

Which viewers support VIFF?

Open VIFF files using Khoros/VisiQuest, ImageMagick, or XnView.

Will the VIFF result match G3 quality?

G3 to VIFF conversion is lossless for document content. Lines, text, and graphics all remain intact.

Does converting G3 to VIFF cost money?

No — standard conversions cost nothing. Premium plans offer higher limits for power users.

Does the converter accept multiple uploads?

Yes — the converter handles multiple files per session. Each G3 upload converts to VIFF on its own.

Does the converter work on mobile devices?

Yes — the G3 to VIFF converter is fully responsive. It works on phones, tablets, and any device with a browser.