CID to OTB Converter

Create over-the-air bitmaps from CID-keyed font characters online

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Mobile Optimized

OTB is designed for resource-constrained devices. Your CID-keyed CJK characters become compact bitmaps ready for mobile and embedded displays.

Lightweight Output

OTB produces extremely small files — essential for over-the-air delivery to devices with limited bandwidth and storage.

Web-Based Conversion

No mobile development SDK needed. Generate OTB bitmaps from CID fonts directly through your browser on any platform.

How to convert CID 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

CID (Character Identifier) is a font architecture developed by Adobe Systems and specified in June 1993 to address the challenges of fonts containing very large glyph sets, particularly for CJK (Chinese, Japanese, Korean) scripts. Traditional PostScript fonts identify glyphs by name, which becomes impractical when a font contains tens of thousands of characters — a typical Japanese font may include over 20,000 glyphs. CID-keyed fonts replace glyph names with numeric identifiers organized by a character collection and ordering (such as Adobe-Japan1 or Adobe-GB1), dramatically reducing overhead for glyph access and subsetting. The architecture defines three PostScript font types: Type 9 (CID-keyed Type 1 outlines), Type 10 (CID-keyed Type 3), and Type 11 (CID-keyed Type 42/TrueType). A primary advantage is efficient handling of massive character sets — the numeric CID approach eliminates the memory and processing cost of maintaining thousands of glyph name strings. CID fonts also support sophisticated CMap resources that map encoding values to CIDs, enabling a single font to serve multiple encoding schemes (Unicode, Shift-JIS, Big5) without duplicating glyph data. The architecture integrates well with PDF subsetting, allowing documents to embed only the glyphs actually used. CID-keyed technology laid the foundation for CJK support in both OpenType and modern PDF workflows, and remains active in print production and document processing systems worldwide.
Developer: Adobe Systems
Initial release: June 11, 1993
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 CID to OTB?

OTB bitmaps are designed for mobile and embedded device displays where compact, simple image data is required for character rendering.

How do I view OTB images?

ImageMagick and mobile development toolkits handle OTB files. The format is intended for device-side rendering rather than desktop viewing.

Is OTB useful for CJK characters?

Yes — converting CID glyphs to OTB creates compact character bitmaps suitable for mobile screens that need to display CJK text.

Does OTB support color?

OTB is typically monochrome, optimized for minimal size. CJK glyph strokes render as clean black-on-white bitmap patterns.

Is CID to OTB free on Convertio?

Completely free. Upload your CID font, convert, and download the OTB output without any fees or registration.