OTB to PGX Converter

Seamless OTB to PGX image conversion, done in the cloud

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Lightning Fast

OTB files are small and convert to PGX in seconds. The cloud-based engine handles the transformation quickly so you can download right away.

Secure Processing

Uploaded OTB images are erased right after conversion, and the resulting PGX files are purged within 24 hours — your data stays private.

Browser-Based Tool

No software to download — convert OTB to PGX entirely in your web browser. Works on any device with an internet connection.

How to convert OTB 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

OTB (Over-the-Air Bitmap) is a monochrome image format developed by Nokia as part of their Smart Messaging specification in 1997, designed for transmitting small graphics — operator logos, group graphics, and picture messages — to Nokia mobile phones via SMS. OTB files contain 1-bit (black and white) images at small fixed resolutions, typically 72x14 pixels for operator logos and 72x28 pixels for group graphics, encoded in a compact binary format suitable for embedding within the payload of SMS text messages. The format uses a simple structure: a header byte indicating whether the image is an operator logo or group graphic, width and height values, and the raw bitmap data where each bit represents one pixel packed eight per byte. The extremely tight format — designed to fit within a single SMS message (140 bytes maximum payload, shared with addressing overhead) — reflects the severe constraints of mobile communication in the late 1990s. Nokia's Smart Messaging system was one of the first commercial implementations of rich content delivery to mobile phones, and OTB images represented the entire visual content capability of Nokia handsets before MMS and mobile data browsing arrived. One advantage is the format's historical role as a pioneer of mobile visual messaging: OTB images were among the first graphics that ordinary consumers could send to each other's phones, predating MMS, camera phones, and smartphones by nearly a decade. The format's minimal footprint is another characteristic — entire images fit in a few dozen bytes, reflecting an era of extreme bandwidth constraints. OTB files are supported by ImageMagick, various Nokia phone management tools, and specialty mobile format utilities.
Developer: Nokia
Initial release: 1997
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 OTB to PGX?

OTB is tied to Nokia mobile phones. Switching to PGX gives you JPEG 2000 test image format and broad support across platforms, browsers, and devices.

How do I open a PGX file?

Software that handles PGX includes ImageMagick, OpenJPEG, GIMP — giving you options on every major operating system.

Does converting OTB to PGX affect quality?

Your image content stays intact during conversion. Any differences depend on PGX characteristics — such as color depth or compression method.

Is OTB to PGX conversion free?

Standard conversions are available for free on Convertio. Larger volumes or higher usage may benefit from a premium plan for additional capacity.

How long does OTB to PGX conversion take?

Most OTB to PGX conversions complete within a few seconds. The lightweight nature of OTB images means fast processing times.