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OTB to DJVU Converter

OTB to DJVU — put your images into document format

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Effortless Process

Converting OTB to DJVU takes just a few clicks — no technical knowledge required. Upload, choose your format, and download the result.

Any Device Works

Convert OTB to DJVU from Windows, macOS, Linux, or mobile — the browser-based tool adapts to any screen size and operating system.

Privacy Protected

Your OTB files are deleted immediately after conversion to DJVU. Converted files are automatically removed from servers within 24 hours.

How to convert OTB to DJVU

1

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

2

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

3

Let the file convert and you can download your djvu 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
DjVu (pronounced "deja vu") is a document format developed at AT&T Labs by Yann LeCun, Leon Bottou, Patrick Haffner, and Paul Howard, first released in 1996. The format was specifically designed for storing scanned documents and images at very high compression ratios while maintaining visual quality suitable for on-screen reading. DjVu achieves this through a layered approach: the document image is separated into a foreground layer (text and line art at full resolution), a background layer (photographs and textures at reduced resolution), and a mask layer that determines which layer is visible at each pixel. This separation, combined with purpose-built compression algorithms for each layer type, typically produces files 5-10 times smaller than equivalent JPEG or PDF scans. One advantage is exceptional compression on scanned pages — a 300 DPI color scan that might occupy 25 MB as TIFF or 500 KB as JPEG typically compresses to 40-80 KB in DjVu while preserving legible text. The progressive rendering model is another strength: DjVu files stream efficiently over networks, displaying a readable low-resolution version almost immediately while progressively refining to full quality. The format supports multi-page documents, embedded text layers for searchability, hyperlinks, annotations, and a shared dictionary mechanism that further compresses collections of similar pages. DjVu is widely used by libraries and archives for digitized historical documents and manuscripts.
Developer: AT&T Labs
Initial release: 1996

Frequently Asked Questions

Why convert OTB to DJVU?

DJVU is a compressed document format for scanned images. Wrapping your OTB image in DJVU makes it easier to distribute, print, and archive alongside text content.

What programs open DJVU files?

Open DJVU using DjVu Browser Plugin, WinDjView, Sumatra PDF, Evince. Cross-platform support means you can access these files on virtually any system.

What exactly is the OTB format?

OTB is an Over-The-Air bitmap format for early Nokia phones. Originally from Nokia mobile phones, it has become a legacy format — conversion is the most practical way to use these images today.

Are my uploaded files kept private?

Yes — your OTB files are deleted immediately after processing. The resulting DJVU files are also removed from servers within 24 hours.

Is OTB to DJVU conversion free?

Yes — Convertio offers free OTB to DJVU conversion. Premium options exist for users who need more capacity or faster processing speeds.

Does this converter work on mobile devices?

Yes — Convertio runs entirely in the browser. You can convert OTB to DJVU on phones, tablets, or desktops without installing anything.