| Image Processing Toolbox™ | |
labd = lab2double(lab)
labd = lab2double(lab) converts an M-by-3 or M-by-N-by-3 array of L*a*b* color values to class double. The output array labd has the same size as lab.
The Image Processing Toolbox software follows the convention
that double-precision
arrays contain 1976 CIE
values.
arrays that
are uint8 or uint16 follow the
convention in the ICC profile specification (ICC.1:2001-4, www.color.org)
for representing
values as unsigned 8-bit or 16-bit integers.
The ICC encoding convention is illustrated by these tables.
Value (L*) | uint8 Value | uint16 Value |
|---|---|---|
0.0 | 0 | 0 |
100.0 | 255 | 65280 |
100.0 + (25500/65280) | None | 65535 |
Value (a* or b*) | uint8 Value | uint16 Value |
|---|---|---|
-128.0 | 0 | 0 |
0.0 | 128 | 32768 |
127.0 | 255 | 65280 |
127.0 + (255/256) | None | 65535 |
lab is a uint8, uint16, or double array that must be real and nonsparse. labd is double.
Convert full intensity neutral color (white) from uint8 to double.
lab2double(uint8([255 128 128])) ans = 100 0 0
applycform, lab2uint8, lab2uint16, makecform, whitepoint, xyz2double, xyz2uint16
For a full list of the toolbox color space conversion functions, see Color Space Conversions.
| isrgb | lab2uint16 | |
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