2016.11.21 19:21 "Re: [Tiff] 12 bit byte format", by Kemp Watson

Do you have control of the original writing end of the data? If so, why not store as 16-bit? Vastly easierŠ

W. Kemp Watson
kemp@objectivepathology.com

Objective Pathology Services Limited
www.objectivepathology.com
tel. +1 (416) 970-7284

From: <tiff-bounces@lists.maptools.org> on behalf of Aaron Boxer <boxerab@gmail.com>

I am decompressing 12 bit RGB images, on little endian system.

Each channel is stored in 3 nibbles: for example red is stored as

 0xR2 R1 R0

where R2 is the largest address, R0 is the smallest.

When reading a strip, the nibbles are stored in the memory buffer as follows,
of increasing memory address: in order

(brackets indicate bytes)

Lowest address.... (R1 R2) (G2 R0) (G0 G1) (B1 B2) (R2 B0) (R1 R0)....

Is it possible for libtiff to store the nibbles as follows:

R0 R1 R2 G0 G1 G2 B0 B1 B2............

(sorry for the non-standard notation here)