PEF Image to G4 conversion is the process of transforming a Pentax Electronic File (PEF) raw image—captured by Pentax digital cameras—into a G4 (Group 4) CCITT-compressed bitmap format commonly used for black-and-white scanned images and fax data. This conversion decodes the sensor-level raw data, applies demosaicing and tonal adjustments as needed, then renders and compresses the final image into the bilevel G4 format for archival, faxing, or document workflows.
Related guides
Practical guides to help you choose formats, preserve quality, and avoid common conversion problems.
WebP has quietly become the default image format of the modern web, delivering 25-35% smaller files than JPG and PNG with universal browser support. This 2026 guide covers current adoption stats, browser compatibility, WordPress integration, conversion workflows, and when to choose WebP over AVIF for optimal Core Web Vitals performance.
Read guide →Not sure whether to save your image as PNG or JPG? This detailed comparison covers compression, transparency, file size, web performance, and real-world use cases so you can pick the right format every time — with conversion links when you need to switch.
Read guide →Learn how to convert HEIC to JPG for maximum compatibility. This guide explains what HEIC is, why iPhones use it, the key differences between HEIC and JPG, and walks through every conversion method including online tools, iPhone settings, Windows, and Mac.
Read guide →Drag your .PEF 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.
PEF files use the MIME type image/x-pentax-pef and are primarily raw image files containing unprocessed data. G4 files typically have the MIME type image/g3fax and employ Group 4 fax compression, commonly used in fax machines and document imaging. The conversion from PEF to G4 involves compressing image data into a bi-level format suitable for monochrome displays and faxing.
The G4 (.G4) format is commonly used for image. Understanding its characteristics can be helpful when converting to or from other formats like PEF Image.
While specific technical details aren't available here, G4 files generally serve the purpose of storing image effectively within their domain.
Our Online PEF to G4 Converter provides a simple and efficient way to convert your PEF Image files into the G4 format. Designed for users who require fast and high-quality image conversions, this tool ensures your images are ready for use in various applications without any hassle.
PEF Image files are raw images captured by Pentax cameras, preserving maximum detail and color information. In contrast, G4 is a compressed, black-and-white image format optimized for fax transmissions and document storage. While PEF is ideal for photographic editing, G4 offers smaller file sizes suitable for efficient storage and transfer.
Keep source PEF files under 250MB for fastest web conversions; larger files may be slower or require a desktop tool.
Preserve image detail by performing tonal and sharpening adjustments on a grayscale intermediate before converting to bilevel; avoid direct raw-to-bilevel without previewing.
For best text and line art results, use adaptive thresholding or Floyd–Steinberg dithering to maintain legibility after G4 compression.
Batch conversion: preprocess PEFs (resize and denoise) in a raw editor or script, then run a dedicated batch tool to produce consistent G4 TIFFs.
This PEF to G4 converter saved me hours of manual work.
Anna M.
Photographer
Easy to use and reliable, perfect for our document workflows.
Mike L.
Office Manager
Love how quickly it converts without losing quality.
Sarah T.
Designer
Start your free PEF to G4 conversion now.
Drag your file here to to upload.
Up to 250MB
Format limitation: G4 is a black-and-white (1-bit) format—color and grayscale nuance will be lost, so convert only when bilevel output is acceptable.