TIFF 6.0 Specification
Final—June 3, 1992
Section 10 for a description of Modified Huffman Compression.
32773 = PackBits compression, a simple byte-oriented run length scheme. See the
PackBits section for details.
Data compression applies only to raster image data. All other TIFF fields are
unaffected.
Baseline TIFF readers must handle all three compression schemes.
Rows and Columns
An image is organized as a rectangular array of pixels. The dimensions of this
array are stored in the following fields:
ImageLength
Tag
= 257 (101.H)
Type = SHORT or LONG
The number of rows (sometimes described as
scanlines)
in the image.
ImageWidth
Tag
= 256 (100.H)
Type = SHORT or LONG
The number of columns in the image, i.e., the number of pixels per scanline.
Physical Dimensions
Applications often want to know the size of the picture represented by an image.
This information can be calculated from ImageWidth and ImageLength given the
following resolution data:
ResolutionUnit
Tag
= 296 (128.H)
Type = SHORT
Values:
1=
2=
3=
No absolute unit of measurement. Used for images that may have a non-square
aspect ratio but no meaningful absolute dimensions.
Inch.
Centimeter.
Default = 2 (inch).
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