G3 to XV Converter

Convert G3 to XV online — digitize fax images free

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Private & Secure

Uploaded G3 files are erased right after conversion. XV results are automatically deleted within 24 hours.

Fax Digitization

Transform legacy G3 images into modern XV format — making archived fax content digitally accessible.

Cloud-Powered Speed

Conversion runs entirely on our servers — your device stays fast and unaffected regardless of file size.

How to convert G3 to XV

1

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

2

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

3

Let the file convert and you can download your xv 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
XV is an alternate file extension for the VIFF (Visualization Image File Format) developed by Khoral Research as part of the Khoros scientific image processing environment, which originated at the University of New Mexico around 1990. The .xv extension and the .viff extension refer to the same underlying format — a container with a 1024-byte header encoding image dimensions, data type (from single-bit to double-precision float and complex numbers), color space, band count, and optional spatial location metadata, followed by color map data and pixel values. The XV extension became common on systems where Khoros was installed alongside other X Window System tools, and in some research communities .xv was preferred over .viff as a shorter alternative. Khoros itself was a pioneering visual programming system where scientists assembled image processing pipelines by wiring together processing nodes in a graphical canvas — an approach that predated and influenced similar environments in MATLAB, LabVIEW, and commercial remote sensing packages. One advantage of the VIFF/XV format is its ability to store data at scientific precision levels — floating-point and complex number pixel values preserve measurement accuracy that would be lost in photographic formats limited to 8-bit or 16-bit integers, making it valuable for spectral analysis, computational physics output, and satellite imagery. The multi-band architecture provides another strength, allowing a single file to hold dozens of spectral channels from multispectral or hyperspectral sensors without splitting data across multiple files. XV files are supported by ImageMagick and can be converted to modern image formats for visualization or publication.
Developer: Khoral Research
Initial release: 1990

Frequently Asked Questions

Why convert G3 to XV?

Converting G3 to XV makes fax content viewable on any device — no specialized fax software required.

How do I open XV files?

XV files can be opened with XV image viewer, ImageMagick, or Khoros tools.

Will image quality be preserved?

The converter preserves all detail from the original G3 file. Monochrome content translates cleanly into XV format.

Is G3 to XV conversion free?

Standard conversions are completely free. Premium plans unlock higher limits and priority processing speed.

Can I convert multiple G3 files at once?

Yes — upload multiple G3 files at once and each will be converted to XV independently for download.

Are my uploaded files kept private?

Absolutely. Uploaded G3 files are deleted after conversion and XV results are purged within 24 hours.