FILM LIGHT Truelight SDI, Руководство пользователя

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Chapter 1 – Introduction
Terminology
Truelight SDI User Guide
3
Terminology
The following is a brief explanation of some key terms used in this guide.
Term Description
LUT Look-up table.
The look-up table is used for mathematical transforms where the range of values that
need to be operated on is limited. In these cases, you can precompute the transform for
all possible input values and store the solutions in a table, where they can be accessed
quickly when the transform is required. You can also use a LUT for transforms that
cannot be easily described or modelled by a formula—in this case the table may be the
data itself, or the data resampled in some way.
When the number of possible input values is too large to store the solution for every
input, the table may contain the solutions to a subsampled input space. In this case, the
solution for a value that is not included in the table is approximated by interpolating
between nearby values.
When a solution depends on only one input value, the transform or function is referred
to as one-dimensional, and the LUT is called a 1D LUT. In digital colour management,
transforms generally depend on all three primary colours, so a 3D LUT is often used.
Since extra dimensions increase the total number of input value combinations
substantially, practical 3D LUTS always subsample the input space, often on a regular
cubic lattice. In colour management, 3D LUTs are sometimes referred to as
cubes .