LRF to OTB Converter

Free LRF to OTB conversion — on-the-air bitmap format

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Tiny Bitmap Output

Extract visual content from LRF ebooks and render it as compact OTB bitmaps — originally designed for mobile splash screens.

Cloud Processing

The conversion runs on remote servers. No software to install and no load on your device — just upload and download.

Automatic Deletion

Uploaded LRF files are removed after processing. OTB output files are purged from servers automatically within 24 hours.

How to convert LRF 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

LRF is the file format associated with Sony's BBeB (Broadband eBook) specification, jointly developed by Sony and Canon and introduced in 2004 with the Sony Librie EBR-1000EP — the world's first commercial E Ink e-reader. The format supports both reflowable text and fixed-layout page rendering, embedding fonts, images, vector graphics, and metadata within a compact binary container. LRF files use a block-based internal structure with object trees describing page layouts, text streams, image resources, and table of contents navigation. Sony's Reader devices and the companion desktop software (Sony Reader Library) served as the primary ecosystem for LRF content throughout the mid-2000s. A key advantage was its early adoption of high-quality font embedding and text rendering optimized specifically for E Ink displays, delivering a reading experience noticeably superior to many competing formats of the era. The format also supported bookmark synchronization, dictionary lookups, and annotations within the Sony Reader ecosystem. However, Sony officially discontinued BBeB/LRF support in 2010, migrating its Reader platform to the industry-standard EPUB format. Today LRF files are primarily encountered in personal ebook collections from that period and can be converted to modern formats using tools like Calibre. The format remains a historically significant milestone as the native format of the device category that launched the modern e-reader revolution.
Developer: Sony
Initial release: 2004
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 LRF to OTB?

OTB produces small on-the-air bitmaps for mobile phone splash screens. It extracts LRF page visuals for constrained displays.

Which apps can open OTB files?

ImageMagick handles OTB format. The format was primarily designed for Nokia and other early mobile phone startup images.

What are the constraints of OTB?

OTB is monochrome and low-resolution — designed for the tiny screens of early mobile phones, not for detailed image viewing.

Is OTB still relevant today?

OTB is a legacy format for vintage mobile phones. For modern use, PNG or WEBP are far more practical image choices.

Is LRF to OTB free?

Convertio offers free LRF to OTB conversion. Premium tiers provide higher file limits and faster processing speeds.