G4 to RGBA Converter

Convert G4 files to RGBA — instant online tool

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Server-Side Engine

All processing happens in the cloud. Your computer stays free while G4 converts to RGBA on our servers.

Legacy Format Bridge

G4 is a legacy format. Converting to RGBA brings your fax archives into modern, widely accessible formats.

Safe Conversion

Your G4 file is removed right after processing. The RGBA download is auto-deleted within 24 hours.

How to convert G4 to RGBA

1

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

2

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

3

Let the file convert and you can download your rgba 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
RGBA is a raw (headerless) image format that extends the RGB color model with a fourth channel for alpha transparency. Each pixel is stored as four consecutive sample values — red, green, blue, and alpha — written sequentially in scanline order with no container structure, headers, or compression. The alpha channel specifies opacity for each pixel independently: a maximum value means fully opaque, zero means fully transparent, and intermediate values produce semi-transparency. Like its three-channel counterpart, RGBA files require the image dimensions and bit depth to be specified externally since the raw data stream contains no metadata. The format supports 8-bit (four bytes per pixel, 32-bit total), 16-bit, and floating-point channel depths. In compositing workflows, the alpha channel enables layering operations where foreground elements are blended over backgrounds according to their per-pixel opacity — the mathematical foundation for all modern image compositing, described by Porter and Duff in their seminal 1984 paper on digital compositing. One advantage is direct framebuffer compatibility: modern GPU hardware natively processes 32-bit RGBA pixels, so raw RGBA data can be uploaded to texture memory or written from render targets without any format conversion, critical for real-time graphics applications and game engines. The format's simplicity in representing transparent images provides another practical benefit — scientific visualization, medical imaging, and overlay rendering can produce raw RGBA output that any downstream tool can consume without needing a common container format. RGBA files are handled by ImageMagick, FFmpeg, and various graphics and compositing tools.
Initial release: 1990

Frequently Asked Questions

Why convert G4 to RGBA?

RGBA is widely supported by image viewers and browsers — converting from G4 eliminates the need for fax tools.

Which apps open RGBA files?

Open RGBA files using IrfanView, GIMP, or ImageMagick.

Is the converted RGBA file high quality?

Document content stays crisp and readable. The converter maintains G4 image fidelity in the RGBA result.

Do I need to pay for this conversion?

No cost for standard G4 to RGBA conversions. Premium plans add faster processing and increased file limits.

Does this tool handle multiple files?

Yes — batch upload is supported. Drop multiple G4 files and each one converts to RGBA for separate download.

What platforms support this converter?

The converter works in any modern web browser — Windows, macOS, Linux, Android, iOS. No installation required.