Class LogLuvConversion
java.lang.Object
net.sourceforge.jiu.color.conversion.LogLuvConversion
Convert from LogLuv color representation to RGB color space and
from LogL to grayscale.
This implementation is based on the file tif_luv.c
which
is part of the TIFF library libtiff.
The original implementation was written by Greg W. Larson.
Learn more about the color type and its encoding on Greg's page LogLuv Encoding for TIFF Images.
- Since:
- 0.10.0
- Author:
- Marco Schmidt
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Field Summary
FieldsModifier and TypeFieldDescriptionprivate static final double
private static final short[]
private static final double
private static final double[]
private static final int
private static final int
private static final float
private static final float
private static final double
private static final double
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Constructor Summary
Constructors -
Method Summary
Modifier and TypeMethodDescriptionprivate static byte
convertDoubleToByte
(double d) static double
convertLogL10toY
(int p10) Converts an unsigned 10 bit value (the argument must lie in the interval 0 to 1023) to adouble
luminance (brightness) value between0.0
and1.0
.static void
convertLogL16toGray8
(byte[] logl, byte[] gray, int num) Converts a number of 16 bit LogL samples to 8 bit grayscale samples.static double
convertLogL16toY
(int p16) Converts a signed 16 bit value (the argument must lie in the interval -32768 to 32767) to adouble
luminance (brightness) value between0.0
and1.0
.static void
convertLogLuv24InterleavedtoRGB24Planar
(byte[] logluv, byte[] red, byte[] green, byte[] blue, int num) Converts a number of 24 bit LogLuv pixels to 24 bit RGB pixels.static void
convertLogLuv32InterleavedtoRGB24Planar
(byte[] logluv, byte[] red, byte[] green, byte[] blue, int num) Converts a number of 32 bit LogLuv pixels to 24 bit RGB pixels.
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Field Details
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M_LN2
private static final double M_LN2- See Also:
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UVSCALE
private static final double UVSCALE- See Also:
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UV_SQSIZ
private static final float UV_SQSIZ- See Also:
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UV_NDIVS
private static final int UV_NDIVS- See Also:
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UV_VSTART
private static final float UV_VSTART- See Also:
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UV_NVS
private static final int UV_NVS- See Also:
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U_NEU
private static final double U_NEU- See Also:
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V_NEU
private static final double V_NEU- See Also:
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USTART
private static final double[] USTART -
NCUM
private static final short[] NCUM
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Constructor Details
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LogLuvConversion
private LogLuvConversion()
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Method Details
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convertLogL10toY
public static double convertLogL10toY(int p10) Converts an unsigned 10 bit value (the argument must lie in the interval 0 to 1023) to adouble
luminance (brightness) value between0.0
and1.0
. This conversion is needed by both LogLuv to XYZ and LogL to grayscale.- Parameters:
p10
- input LogL value- Returns:
- double value with luminance, between 0 and 1
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convertLogL16toY
public static double convertLogL16toY(int p16) Converts a signed 16 bit value (the argument must lie in the interval -32768 to 32767) to adouble
luminance (brightness) value between0.0
and1.0
. This conversion is needed by both LogLuv to XYZ and LogL to grayscale.- Parameters:
p16
- input LogL value- Returns:
- double value with luminance, between 0 and 1
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convertDoubleToByte
private static byte convertDoubleToByte(double d) -
convertLogLuv24InterleavedtoRGB24Planar
public static void convertLogLuv24InterleavedtoRGB24Planar(byte[] logluv, byte[] red, byte[] green, byte[] blue, int num) Converts a number of 24 bit LogLuv pixels to 24 bit RGB pixels. Each LogLuv pixel is stored as three consecutive bytes in thelogluv
byte array. The first byte and the top two bits of the second are the LogL value, the remaining 14 bits are an index that encodes u and v.- Parameters:
logluv
- byte array with LogLuv data, must be at least num * 3 bytes largered
- the byte samples for the red channel will be written to this arraygreen
- the byte samples for the green channel will be written to this arrayblue
- the byte samples for the blue channel will be written to this arraynum
- number of pixels to be converted
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convertLogLuv32InterleavedtoRGB24Planar
public static void convertLogLuv32InterleavedtoRGB24Planar(byte[] logluv, byte[] red, byte[] green, byte[] blue, int num) Converts a number of 32 bit LogLuv pixels to 24 bit RGB pixels. Each LogLuv pixel is stored as four consecutive bytes in thelogluv
byte array. The first two bytes represent the LogL value (most significant bytefirst), followed by the u value and then the v value.- Parameters:
logluv
- byte array with LogLuv data, must be at least num * 4 bytes largered
- the byte samples for the red channel will be written to this arraygreen
- the byte samples for the green channel will be written to this arrayblue
- the byte samples for the blue channel will be written to this arraynum
- number of pixels to be converted
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convertLogL16toGray8
public static void convertLogL16toGray8(byte[] logl, byte[] gray, int num) Converts a number of 16 bit LogL samples to 8 bit grayscale samples.- Parameters:
logl
- byte array with LogL samples, each 16 bit sample is stored as two consecutive bytes in order most-significant-byte least-significant-byte (network byte order); the array must be at least num * 2 entries largegray
- the byte array to which the converted samples will be writtennum
- the number of samples to be converted
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