G3 to PCD Converter

Free G3 to PCD conversion — browser-based tool

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Private & Secure

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

Fax Content Access

Make G3 content viewable in PCD format — no fax machines or specialized legacy viewers required.

Nothing to Install

The G3 to PCD conversion happens in your browser — no software to download or configure on your device.

How to convert G3 to PCD

1

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

2

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

3

Let the file convert and you can download your pcd 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
PCD (Photo CD) is a proprietary image format developed by Eastman Kodak in partnership with Philips, launched in 1992 as a system for transferring 35mm film photographs to compact discs for digital viewing and printing. Each PCD file stores a single photograph at five different resolutions in a hierarchical structure called an Image Pac: Base/16 (192x128), Base/4 (384x256), Base (768x512), 4Base (1536x1024), and 16Base (3072x2048), with optional 64Base (6144x4096) on Pro Photo CD discs. Images are stored in Kodak's proprietary YCC color space (a variant of CIE Lab via the Photo YCC color model), which captures a wider gamut than sRGB, at 8 bits per component in the luminance channel and subsampled chrominance. The multi-resolution pyramid is encoded using a progressive scheme: the Base image is stored directly, and each higher resolution is stored as a residual (difference) that refines the upscaled previous level, keeping the total file size manageable. One advantage is the exceptional scan quality: Photo CD scans were performed on Kodak's professional PIW (Photo Imaging Workstation) scanners by trained operators, producing consistently excellent results from 35mm negatives and slides — often better than what contemporary consumer flatbed scanners could achieve. The multi-resolution structure is another notable feature: a single PCD file serves needs from thumbnail browsing to high-resolution printing without separate file versions. PCD files can be read by Adobe Photoshop, ImageMagick, GIMP (via plugin), IrfanView, and XnView, ensuring continued access to the millions of Photo CD images created during the format's commercial peak in the 1990s.
Developer: Eastman Kodak
Initial release: 1992

Frequently Asked Questions

Why convert G3 to PCD?

G3 files require specialized fax viewers. Converting to PCD lets anyone open the content easily.

How do I view a PCD file?

Use IrfanView, XnView, or Adobe Photoshop to view PCD files.

Will my G3 content stay sharp in PCD?

Full resolution is preserved during G3 to PCD conversion. Text and graphics remain sharp and clear.

Is there a charge for G3 to PCD?

Basic conversions are free. Premium subscriptions provide priority processing and expanded daily capacity.

Can I process many G3 files in one go?

Absolutely — add several G3 files at once. Each gets its own PCD conversion and individual download link.

Is my data secure during conversion?

Uploaded G3 files are deleted immediately after conversion. PCD results are automatically removed within 24 hours.