enum DataMask extends java.lang.Enum<DataMask>
Encapsulates data masks for the data bits in a QR code, per ISO 18004:2006 6.8. Implementations of this class can un-mask a raw BitMatrix. For simplicity, they will unmask the entire BitMatrix, including areas used for finder patterns, timing patterns, etc. These areas should be unused after the point they are unmasked anyway.
Note that the diagram in section 6.8.1 is misleading since it indicates that i is column position and j is row position. In fact, as the text says, i is row position and j is column position.
Enum Constant and Description |
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DATA_MASK_000
000: mask bits for which (x + y) mod 2 == 0
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DATA_MASK_001
001: mask bits for which x mod 2 == 0
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DATA_MASK_010
010: mask bits for which y mod 3 == 0
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DATA_MASK_011
011: mask bits for which (x + y) mod 3 == 0
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DATA_MASK_100
100: mask bits for which (x/2 + y/3) mod 2 == 0
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DATA_MASK_101
101: mask bits for which xy mod 2 + xy mod 3 == 0
equivalently, such that xy mod 6 == 0
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DATA_MASK_110
110: mask bits for which (xy mod 2 + xy mod 3) mod 2 == 0
equivalently, such that xy mod 6 < 3
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DATA_MASK_111
111: mask bits for which ((x+y)mod 2 + xy mod 3) mod 2 == 0
equivalently, such that (x + y + xy mod 3) mod 2 == 0
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Modifier and Type | Method and Description |
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(package private) abstract boolean |
isMasked(int i,
int j) |
(package private) void |
unmaskBitMatrix(BitMatrix bits,
int dimension)
Implementations of this method reverse the data masking process applied to a QR Code and
make its bits ready to read.
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static DataMask |
valueOf(java.lang.String name)
Returns the enum constant of this type with the specified name.
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static DataMask[] |
values()
Returns an array containing the constants of this enum type, in
the order they are declared.
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public static final DataMask DATA_MASK_000
public static final DataMask DATA_MASK_001
public static final DataMask DATA_MASK_010
public static final DataMask DATA_MASK_011
public static final DataMask DATA_MASK_100
public static final DataMask DATA_MASK_101
public static final DataMask DATA_MASK_110
public static final DataMask DATA_MASK_111
public static DataMask[] values()
for (DataMask c : DataMask.values()) System.out.println(c);
public static DataMask valueOf(java.lang.String name)
name
- the name of the enum constant to be returned.java.lang.IllegalArgumentException
- if this enum type has no constant with the specified namejava.lang.NullPointerException
- if the argument is nullfinal void unmaskBitMatrix(BitMatrix bits, int dimension)
Implementations of this method reverse the data masking process applied to a QR Code and make its bits ready to read.
bits
- representation of QR Code bitsdimension
- dimension of QR Code, represented by bits, being unmaskedabstract boolean isMasked(int i, int j)