AWARE [SYSTEMS] Imaging expertise for the Delphi developer
AWare Systems, Imaging expertise for the Delphi developer, Home Extension TIFF Tag Indexed

TIFF Tag Reference

TIFF Tag Reference
TIFF Tag Search

Extension TIFF Tags

Previous Tag
Next Tag

Contact

Information: info@awaresystems.be
Helpdesk: support@awaresystems.be
Sales: sales@awaresystems.be



Valid HTML 4.01!



TIFF Tag Indexed

IFDImage
Code346 (hex 0x015A)
NameIndexed
TypeSHORT
Count1
Default0 (not indexed)

Description

Aims to broaden the support for indexed images to include support for any color space.

Indexed images are images where the pixels do not represent color values, but rather an index (usually 8-bit) into a separate color table, the ColorMap.

ColorMap is required for an Indexed image.

The specification supplement defines these values:

0 = not indexed
1 = indexed

The specification supplement not being very clear, presumably it means that palette images can be coded either:

- With PhotometricInterpretation = PaletteColor. A ColorMap must be included, and the ColorMap values are RGB. If the Indexed field is included, it must equal 0, but it is probably best to not include it in this case.
- With PhotometricInterpretation = some other color space. A ColorMap must be included, and the ColorMap values are to be interpreted as indicated by the PhotometricInterpretation. The Indexed field must be included, and it must equal 1.

In both cases, SamplesPerPixel must be 1.

This explaines the specification supplement warning not to use both the Indexed flag and PhotometricInterpretation = PaletteColor for the same image.

Related tags

PhotometricInterpretation
ColorMap

See also

TIFF Specification Supplement 1