GIF to PGX Converter

Convert GIF images to PGX reference format online

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JPEG 2000 Testing

PGX is essential for JPEG 2000 codec development and verification. Convert your GIF into reference data for conformance testing.

Online Processing

No JPEG 2000 development tools needed. Convertio creates the PGX file online — upload the GIF and download the result.

Secure Processing

Your GIF is removed from servers right after conversion. The PGX output is deleted within 24 hours for data privacy.

How to convert GIF to PGX

1

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

2

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

3

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

About formats

GIF (Graphics Interchange Format) was introduced by CompuServe on June 15, 1987 as a platform-independent image format for transmitting color graphics over the CompuServe online service's modem-speed connections. The format uses LZW (Lempel-Ziv-Welch) lossless compression on indexed-color images with a palette of up to 256 colors selected from a 24-bit RGB color space. GIF's most distinctive capability is animation: multiple image frames can be stored sequentially within a single file, each with independent delay timing, disposal methods, and local color palettes, enabling short looping animations without any video codec or player. The format also supports binary transparency (one palette entry designated as fully transparent) and interlaced display for progressive rendering. GIF became synonymous with web culture — animated GIFs proliferated across early websites, messaging platforms, and social media, evolving into a communication medium in their own right. One advantage is universal animation support — GIF animations play natively in every web browser, email client, messaging app, and social platform without plugins, codecs, or compatibility concerns, a level of ubiquity no other animation format has achieved. The lossless compression on palette-based images provides another strength: graphics with flat colors, text, and sharp edges (logos, diagrams, UI elements) compress efficiently without the artifacts that affect JPEG. Although the LZW patents that once threatened GIF's use expired in 2004, and newer formats like WebP and AVIF offer superior compression with full-color animation, GIF's cultural entrenchment keeps it irreplaceable for casual animated content.
Developer: CompuServe
Initial release: June 15, 1987
PGX is a simple single-component raster image format defined as part of the JPEG 2000 standard (ISO/IEC 15444) for use in conformance testing and verification of JPEG 2000 codec implementations. Introduced around 2000 alongside the JPEG 2000 specification itself, PGX files store a single image component (one color channel or grayscale plane) with a text header followed by raw pixel data, providing an unambiguous reference representation against which encoder and decoder outputs can be compared sample by sample. The header is a single ASCII line specifying endianness (ML for big-endian, LM for little-endian), signedness (+ for unsigned, - for signed), bit depth (1 to 32 bits), width, and height. The pixel data follows as raw binary values, each occupying the minimum number of bytes needed for the specified bit depth, with one value per pixel. For multi-component images (like RGB), each component is stored in a separate PGX file. The format's deliberate simplicity — no compression, no metadata, no multi-channel support — ensures there are no ambiguities in interpretation that could mask codec bugs. One advantage is verification precision: PGX's uncompressed, exactly-specified representation allows bit-exact comparison of decoded JPEG 2000 output against reference images, essential for certifying that a codec implementation conforms to the standard. The format's role in the JPEG 2000 conformance testing framework means it is implemented by every serious JPEG 2000 codec (OpenJPEG, Kakadu, etc.) and used in the official ISO conformance test suite. PGX files can also be processed by ImageMagick and various JPEG 2000 development tools.
Initial release: 2000

Frequently Asked Questions

Why convert GIF to PGX?

PGX is the reference image format for JPEG 2000 conformance testing — converting provides input data in the format required for codec verification.

What uses PGX files?

JPEG 2000 codec test suites, OpenJPEG, Kakadu, and other JPEG 2000 implementations use PGX for reference image data and conformance testing.

Is PGX a simple format?

Yes — PGX has a minimal ASCII header followed by raw pixel values. It stores a single image component per file for maximum simplicity.

Does PGX support color?

PGX stores one component per file. Color images require separate PGX files for each channel (e.g., three files for RGB).

Is PGX widely used?

PGX is specific to JPEG 2000 testing and development. For general imaging, standard formats like PNG or JP2 are more practical.

GIF to PGX Quality Rating

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