PGM to OTB Converter

Online PGM to OTB conversion — instant results

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Secure Conversion

File privacy is guaranteed — PGM uploads are removed after conversion, and OTB results are deleted within 24 hours.

Server-Side Conversion

PGM to OTB conversion happens in the cloud. Your computer or phone is not burdened by any processing work whatsoever.

Simple Workflow

Upload PGM, choose OTB, download your file — three clear steps with no complicated settings or confusing interfaces.

How to convert PGM to OTB

1

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

2

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

3

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

About formats

PGM (Portable Graymap) is the grayscale member of the Netpbm image format family, created by Jef Poskanzer in 1988 as part of the Pbmplus toolkit for Unix systems. PGM stores single-channel intensity images where each pixel holds a gray value from 0 (black) to a user-specified maximum (typically 255 for 8-bit or 65535 for 16-bit). The format exists in ASCII (magic number P2), where pixel values are written as decimal text numbers separated by whitespace, and binary (magic number P5), where values are stored as raw bytes. Both variants begin with a header specifying the magic number, width, height, and maximum gray value. PGM was designed as the grayscale intermediate in Netpbm's convert-process-convert pipeline philosophy: source images from any format are converted to PGM, processed using Netpbm's extensive command-line tool library, then converted to the target format. One advantage is format transparency — the ASCII variant makes image data directly readable by humans and trivially processable by text tools like awk and grep, invaluable for debugging and education. The scientific and computer vision community's adoption is another strength: PGM's straightforward single-channel representation makes it a natural format for image analysis algorithms, and many academic papers and course materials use PGM examples. The format is supported by ImageMagick, GIMP, and countless image processing libraries, and remains standard input for many research tools and benchmarks.
Developer: Jef Poskanzer
Initial release: 1988
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

Frequently Asked Questions

Why convert PGM to OTB?

OTB is widely supported and offers simple bitmap for embedded use — ideal when PGM is too specialized for your needs.

What programs open OTB files?

Open OTB with ImageMagick, Netpbm tools. On mobile devices, built-in gallery apps or third-party viewers also handle this format.

Will I lose image quality converting PGM to OTB?

Your image retains its current quality level. Converting from PGM to OTB does not introduce additional degradation to the visual data.

Can I convert multiple PGM files to OTB at once?

Yes — upload several PGM files simultaneously and convert them all to OTB in a single batch operation.

Is the PGM to OTB conversion instant?

Yes, for most files the conversion happens almost instantly. Larger PGM images may take a few extra seconds to process.

Do I need to create an account to convert?

No sign-up necessary. The converter works without an account for regular PGM to OTB conversions.