CBDT/CBLC

フォントファイルにビットマップカラー絵文字を埋め込むためのOpenTypeテーブル「Color Bitmap Data Table」と「Color Bitmap Location Table」。

CBDT (Color Bitmap Data Table) and CBLC (Color Bitmap Location Table) store pre-rendered color bitmap images directly in an OpenType font file. Google Noto Color Emoji uses this format.

CBLC provides an index mapping glyphs to their bitmap data locations, while CBDT contains the actual image data (typically PNG). Multiple "strike" sizes can be included for different display resolutions.

While CBDT produces consistent, high-quality results, the embedded bitmaps make font files large. Google's Noto Color Emoji font is approximately 10MB, compared to kilobytes for a standard text font.