JEITA CP-3451
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4.5 Basic Structure of Image Data
4.5.1 Basic Structure of Primary Image Data
Image data employs following existing image formats, depending on the image data type:
· RGB uncompressed data: Baseline TIFF Rev. 6.0 RGB Full Color Images,
· YCbCr uncompressed data: TIFF Rev. 6.0 Extensions YCbCr Images,
· JPEG compressed data: JPEG Baseline ADCT.
For compressed data, the attribute information required by the DSC application shall be recorded in APP1. Data
writing in APP1 shall be compatible with TIFF. The use of a common method of storing attribute information for both
compressed and uncompressed data results in a simpler format, while the ability to add private tags for additional
information takes advantage of the extensibility of the tag mechanism.
4.5.2 Basic Structure of Uncompressed RGB Data
Uncompressed RGB data is recorded in conformance with Baseline TIFF Rev. 6.0 RGB Full Color Color Images.
Attribute information is recorded in tags specified in TIFF Rev. 6.0. Attribute information specific to Exif is recorded
using private tags reserved in TIFF for this standard. The private tags point to sets of this attribute information (Exif
IFD).
Files are structured as follows (see Figure 5). As in the TIFF standard, the recording location of each IFD value is
not specified:
· File Header,
· 0th IFD,
· 0th IFD Value,
· 1st IFD,
· 1st IFD Value,
· 1st (Thumbnail) Image Data,
· 0th (Primary) Image Data.