TIFF 6.0 Specification
Final—June 3, 1992
sion includes any padded areas of the rightmost and bottom tiles so that all the
tiles in an image are the same size when uncompressed.
All of the following fields are required for tiled images:
Fields
TileWidth
Tag
= 322 (142.H)
Type = SHORT or LONG
N
=1
The tile width in pixels. This is the number of columns in each tile.
Assuming integer arithmetic, three computed values that are useful in the follow-
ing field descriptions are:
TilesAcross = (ImageWidth + TileWidth - 1) / TileWidth
TilesDown = (ImageLength + TileLength - 1) / TileLength
TilesPerImage = TilesAcross * TilesDown
These computed values are not TIFF fields; they are simply values determined by
the ImageWidth, TileWidth, ImageLength, and TileLength fields.
TileWidth and ImageWidth together determine the number of tiles that span the
width of the image (TilesAcross). TileLength and ImageLength together deter-
mine the number of tiles that span the length of the image (TilesDown).
We recommend choosing TileWidth and TileLength such that the resulting tiles
are about 4K to 32K bytes before compression. This seems to be a reasonable
value for most applications and compression schemes.
TileWidth must be a multiple of 16. This restriction improves performance in
some graphics environments and enhances compatibility with compression
schemes such as JPEG.
Tiles need not be square.
Note that ImageWidth can be less than TileWidth, although this means that the
tiles are too large or that you are using tiling on really small images, neither of
which is recommended. The same observation holds for ImageLength and
TileLength.
No default. See also TileLength, TileOffsets, TileByteCounts.
TileLength
Tag
= 323 (143.H)
Type = SHORT or LONG
N
=1
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