![]() |
![]() |
![]() |
![]() |
![]() |
![]() |
![]() |
||||||||||||||||||||
AWARE [SYSTEMS] | ||||||||||||||||||||||||||
![]() |
Extension TIFF Tag Decode | |||||||||||||||||||||||||
TIFF Tag Reference
TIFF Tag Reference Contact
Information: info@awaresystems.be |
TIFF Tag Decode
DescriptionUsed in the TIFF-F and TIFF-FX standards, holds information about the ITULAB (PhotometricInterpretation = 10) encoding. In general, the values are taken in pairs and specify the minimum and maximum output value for each color component. For the base color fax mode, Decode has a count of 6 values and maps the unsigned ITULAB-encoded sample values (Lsample, asample, bsample) to signed L*a*b* values, as follows:
L* = Decode[0] + Lsample x (Decode[1] - Decode[0]) / (2^n -1) where n is the BitsPerSample, either 8 or 12. Another way of looking at this, is saying:
Decode[0], Decode[2] and Decode[4] are the minimum values for L*, a* and b* When PhotometricInterpretation=10 and BitsPerSample=8, the default value for Decode is (0, 100, -21760/255, 21590/255, -19200/255, 31800/255). When PhotometricInterpretation=10 and BitsPerSample=12, the default value for Decode is (0, 100, -348160/4095, 347990/4095, -307200/4095, 511800/4095). Related tagsSee also
RFC 2301 - File Format for Internet Fax |