Package com.google.zxing.common
Class BitMatrix
java.lang.Object
com.google.zxing.common.BitMatrix
- All Implemented Interfaces:
Cloneable
Represents a 2D matrix of bits. In function arguments below, and throughout the common module, x is the column position, and y is the row position. The ordering is always x, y. The origin is at the top-left.
Internally the bits are represented in a 1-D array of 32-bit ints. However, each row begins with a new int. This is done intentionally so that we can copy out a row into a BitArray very efficiently.
The ordering of bits is row-major. Within each int, the least significant bits are used first, meaning they represent lower x values. This is compatible with BitArray's implementation.
- Author:
- Sean Owen, dswitkin@google.com (Daniel Switkin)
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Constructor Summary
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Method Summary
Modifier and TypeMethodDescriptionvoid
clear()
Clears all bits (sets to false).clone()
boolean
void
flip
(int x, int y) Flips the given bit.boolean
get
(int x, int y) Gets the requested bit, where true means black.int[]
int[]
This is useful in detecting the enclosing rectangle of a 'pure' barcode.int
A fast method to retrieve one row of data from the matrix as a BitArray.int
int[]
This is useful in detecting a corner of a 'pure' barcode.int
getWidth()
int
hashCode()
static BitMatrix
parse
(boolean[][] image) Interprets a 2D array of booleans as aBitMatrix
, where "true" means an "on" bit.static BitMatrix
void
Modifies thisBitMatrix
to represent the same but rotated 180 degreesvoid
set
(int x, int y) Sets the given bit to true.void
setRegion
(int left, int top, int width, int height) Sets a square region of the bit matrix to true.void
toString()
Deprecated.void
unset
(int x, int y) void
Exclusive-or (XOR): Flip the bit in thisBitMatrix
if the corresponding mask bit is set.
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Constructor Details
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BitMatrix
public BitMatrix(int dimension) Creates an empty squareBitMatrix
.- Parameters:
dimension
- height and width
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BitMatrix
public BitMatrix(int width, int height) Creates an emptyBitMatrix
.- Parameters:
width
- bit matrix widthheight
- bit matrix height
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Method Details
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parse
Interprets a 2D array of booleans as aBitMatrix
, where "true" means an "on" bit.- Parameters:
image
- bits of the image, as a row-major 2D array. Elements are arrays representing rows- Returns:
BitMatrix
representation of image
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parse
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get
public boolean get(int x, int y) Gets the requested bit, where true means black.
- Parameters:
x
- The horizontal component (i.e. which column)y
- The vertical component (i.e. which row)- Returns:
- value of given bit in matrix
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set
public void set(int x, int y) Sets the given bit to true.
- Parameters:
x
- The horizontal component (i.e. which column)y
- The vertical component (i.e. which row)
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unset
public void unset(int x, int y) -
flip
public void flip(int x, int y) Flips the given bit.
- Parameters:
x
- The horizontal component (i.e. which column)y
- The vertical component (i.e. which row)
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xor
Exclusive-or (XOR): Flip the bit in thisBitMatrix
if the corresponding mask bit is set.- Parameters:
mask
- XOR mask
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clear
public void clear()Clears all bits (sets to false). -
setRegion
public void setRegion(int left, int top, int width, int height) Sets a square region of the bit matrix to true.
- Parameters:
left
- The horizontal position to begin at (inclusive)top
- The vertical position to begin at (inclusive)width
- The width of the regionheight
- The height of the region
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getRow
A fast method to retrieve one row of data from the matrix as a BitArray.- Parameters:
y
- The row to retrieverow
- An optional caller-allocated BitArray, will be allocated if null or too small- Returns:
- The resulting BitArray - this reference should always be used even when passing your own row
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setRow
- Parameters:
y
- row to setrow
-BitArray
to copy from
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rotate180
public void rotate180()Modifies thisBitMatrix
to represent the same but rotated 180 degrees -
getEnclosingRectangle
public int[] getEnclosingRectangle()This is useful in detecting the enclosing rectangle of a 'pure' barcode.- Returns:
left,top,width,height
enclosing rectangle of all 1 bits, or null if it is all white
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getTopLeftOnBit
public int[] getTopLeftOnBit()This is useful in detecting a corner of a 'pure' barcode.- Returns:
x,y
coordinate of top-left-most 1 bit, or null if it is all white
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getBottomRightOnBit
public int[] getBottomRightOnBit() -
getWidth
public int getWidth()- Returns:
- The width of the matrix
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getHeight
public int getHeight()- Returns:
- The height of the matrix
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getRowSize
public int getRowSize()- Returns:
- The row size of the matrix
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equals
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hashCode
public int hashCode() -
toString
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toString
- Parameters:
setString
- representation of a set bitunsetString
- representation of an unset bit- Returns:
- string representation of entire matrix utilizing given strings
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toString
Deprecated.calltoString(String,String)
only, which uses \n line separator always- Parameters:
setString
- representation of a set bitunsetString
- representation of an unset bitlineSeparator
- newline character in string representation- Returns:
- string representation of entire matrix utilizing given strings and line separator
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clone
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toString(String,String)
only, which uses \n line separator always