G4 to MAP Converter

Convert G4 to MAP online — digitize fax images free

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Private & Secure

Uploaded G4 files are erased right after conversion. MAP results are automatically deleted within 24 hours.

Fax Digitization

Transform legacy G4 images into modern MAP 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 G4 to MAP

1

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

2

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

3

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

About formats

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
MAP is an internal raster image format used by ImageMagick, the open-source image processing suite first released by John Cristy at DuPont on August 1, 1990. MAP files store indexed-color (color-mapped) images in ImageMagick's native representation: a color palette (the map) followed by pixel data where each pixel is an index into that palette rather than a direct RGB value. The format provides a compact representation for images with a limited number of distinct colors — each pixel requires only enough bits to index the palette (typically 8 bits for up to 256 colors), compared to the 24 or 32 bits per pixel required by full-color formats. MAP serves primarily as an intermediate format within ImageMagick's processing pipeline, useful when performing operations that benefit from or require palettized representation: color quantization (reducing an image to a specific number of colors), palette manipulation, GIF preparation, and indexed-color analysis. The format is invoked through ImageMagick's standard I/O syntax and can be piped between processing stages without disk overhead. One advantage is direct access to ImageMagick's color quantization and palette management capabilities: MAP format output makes the palette structure explicit and manipulable, enabling workflows where specific palette operations (reordering, remapping, merging) need to be performed between processing steps. The format's integration into the ImageMagick processing ecosystem is another practical strength — any of ImageMagick's extensive image manipulation operations can consume or produce MAP format data, making it a natural intermediate for color-reduction pipelines that ultimately target GIF, PNG with palette, or other indexed-color formats.
Initial release: 1990

Frequently Asked Questions

Why convert G4 to MAP?

Converting G4 to MAP makes fax content viewable on any device — no specialized fax software required.

How do I open MAP files?

MAP files can be opened with ImageMagick, XnView, or specialized image tools.

Will image quality be preserved?

The converter preserves all detail from the original G4 file. Monochrome content translates cleanly into MAP format.

Is G4 to MAP conversion free?

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

Can I convert multiple G4 files at once?

Yes — upload multiple G4 files at once and each will be converted to MAP independently for download.

What happens to my files after conversion?

Your original G4 upload is deleted right after processing. The converted MAP file is removed within 24 hours.