TIFF 6.0 Specification
Final—June 3, 1992
This Field indicates the length of the restart interval used in the compressed image
data. The restart interval is defined as the number of Minimum Coded Units
(MCUs) between restart markers.
Restart intervals are used in JPEG compressed images to provide support for
multiple strips or tiles. At the start of each restart interval, the coding state is reset
to default values, allowing every restart interval to be decoded independently of
previously decoded data. TIFF strip and tile offsets shall always point to the start
of a restart interval. Equivalently, each strip or tile contains an integral number of
restart intervals. Restart markers need not be present in a TIFF file; they are im-
plicitly coded at the start of every strip or tile.
See the JPEG Draft International Standard (ISO DIS 10918-1) for more informa-
tion about the restart interval and restart markers.
If this Field is zero or is not present, the compressed data does not contain restart
markers.
JPEGLosslessPredictors
Tag
= 517 (205.H)
Type = SHORT
N
= SamplesPerPixel
This Field points to a list of lossless predictor-selection values, one per compo-
nent.
The allowed predictors are listed in the following table.
Selection-value
1
2
3
4
5
6
7
Prediction
A
B
C
A+B-C
A+((B-C)/2)
B+((A-C)/2)
(A+B)/2
A, B, and C are the samples immediately to the left, immediately above, and
diagonally to the left and above the sample to be coded, respectively.
See the JPEG Draft International Standard (ISO DIS 10918-1) for more details.
This Field is mandatory whenever the JPEGProc Field specifies one of the
lossless processes (no default).
JPEGPointTransforms
Tag
= 518 (206.H)
Type = SHORT
N
= SamplesPerPixel
106