PFM to G4 conversion is the process of transforming a Portable FloatMap (PFM) high dynamic range raster image into a Group 4 (G4) bi-level, lossless CCITT fax-compatible image format. This conversion typically involves tone mapping and quantization from floating-point grayscale data to a 1-bit black-and-white representation optimized for archival or fax-style use.
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Read guide →Drag your .PFM file from your computer or use the browse function.
Confirm .g4 as the selected destination format.
Click "Convert" and download your converted .G4 file once ready.
PFM files are usually identified with the MIME type image/x-portable-pixmap and store uncompressed or lightly compressed pixel data. G4 files use the MIME type image/g3fax or image/g4fax, employing the CCITT Group 4 compression codec designed for monochrome images. Typical use cases include graphic editing for PFM and document storage or fax transmission for G4.
The G4 (.G4) format is commonly used for image. Understanding its characteristics can be helpful when converting to or from other formats like PFM.
While specific technical details aren't available here, G4 files generally serve the purpose of storing image effectively within their domain.
Our online PFM to G4 converter offers a seamless way to convert your PFM files into the G4 format with just a few clicks. Designed to preserve quality and optimize file size, this tool is ideal for professionals and casual users alike seeking a quick and efficient conversion solution.
PFM files typically store high-quality raster images with less compression, resulting in larger file sizes. In contrast, G4 uses Group 4 fax compression, which is highly efficient for monochrome images and scanned documents. While PFM is often used in imaging applications, G4 is favored in fax and document archiving due to its smaller size and compatibility.
Keep PFM source files under 250MB for fastest processing; large HDR images can be downsampled to reduce conversion time while preserving meaningful detail.
To preserve perceived detail when converting to 1-bit G4, apply local contrast enhancement and choose an error-diffusion dithering algorithm rather than simple global thresholding.
For batch conversions, use a tool or service that supports multi-page TIFF with G4 compression and scripting (CLI) so you can set consistent threshold, DPI, and dithering across files.
Format limitation: G4 is strictly bi-level (1-bit) and cannot store grayscale or color, so any HDR gradients in PFM will be represented via halftone/dither patterns only.
The PFM to G4 converter saved me so much time when preparing scanned images for archiving.
Emma L.
Photographer
Reliable and straightforward conversion with excellent output quality.
Mark D.
IT Specialist
I appreciate how easy it is to convert PFM files to G4 without installing any software.
Nina S.
Designer
Start your free PFM to G4 conversion now.
Drag your file here to to upload.
Up to 250MB
If you need lossless grayscale preservation, consider outputting to TIFF with LZW or ZIP compression instead of G4.