AWARE SYSTEMS
TIFF and LibTiff Mail List Archive

Thread

1994.09.16 04:17 "TIFF Bit Ordering Versus Fill Order", by John M Davison
1994.09.16 17:42 "Re: TIFF Bit Ordering Versus Fill Order", by Sam Leffler
1994.09.19 06:55 "Re: TIFF Bit Ordering Versus Fill Order", by Karsten Spang
1994.09.19 17:34 "Now that you mention bit order...", by Craig Jackson
1994.09.19 23:31 "Re: TIFF Bit Ordering Versus Fill Order", by Jim Arnold
[...]

1994.09.16 17:42 "Re: TIFF Bit Ordering Versus Fill Order", by Sam Leffler

I am confused by the text on page 32 of the TIFF 6.0 Specification that describes the "FillOrder" tag. In particular, let's say I had

What my question boils down to is this: what exactly does "FillOrder" mean?

FillOrder is interpreted as the order of bits in each byte of the raw image data stored in the file. If the bit order is different than the host bit order then each byte of raw image data is bit-reversed before being interpreted by a decoder. Note that since I don't know how to deduce the native bit order at runtime the library has the native bit order built into it as a constant (see TIFFInitOrder in tif_open.c).

        Sam