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Convert integer values using lookup table


B = intlut(A, LUT)


B = intlut(A, LUT) converts values in array A based on lookup table LUT and returns these new values in array B. For example, if A is a vector whose kth element is equal to alpha, then B(k) is equal to the LUT value corresponding to alpha, i.e., LUT(alpha+1).

Class Support

A can be uint8, uint16, or int16. If A is uint8, LUT must be a uint8 vector with 256 elements. If A is uint16 or int16, LUT must be a vector with 65536 elements that has the same class as A. B has the same size and class as A.


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Create an array of integers.

A = uint8([1 2 3 4; 5 6 7 8; 9 10 0 1])
A = 3x4 uint8 matrix

    1    2    3    4
    5    6    7    8
    9   10    0    1

Create a lookup table. In this example, the lookup table is created by following the vector [2 4 8 16] with repeated copies of the vector [0 150 200 250].

LUT = [2 4 8 16 repmat(uint8([0 150 200 255]),1,63)];

Convert the values of A by referring to the lookup table. Note that the first index of the lookup table is 0.

B = intlut(A, LUT)
B = 3x4 uint8 matrix

     4     8    16     0
   150   200   255     0
   150   200     2     4

Extended Capabilities

See Also


Introduced before R2006a

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