Package com.google.zxing
Class BinaryBitmap
java.lang.Object
com.google.zxing.BinaryBitmap
This class is the core bitmap class used by ZXing to represent 1 bit data. Reader objects
accept a BinaryBitmap and attempt to decode it.
- Author:
- dswitkin@google.com (Daniel Switkin)
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Constructor Summary
Constructors -
Method Summary
Modifier and TypeMethodDescriptioncrop
(int left, int top, int width, int height) Returns a new object with cropped image data.Converts a 2D array of luminance data to 1 bit.getBlackRow
(int y, BitArray row) Converts one row of luminance data to 1 bit data.int
int
getWidth()
boolean
boolean
Returns a new object with rotated image data by 90 degrees counterclockwise.Returns a new object with rotated image data by 45 degrees counterclockwise.toString()
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Constructor Details
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BinaryBitmap
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Method Details
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getWidth
public int getWidth()- Returns:
- The width of the bitmap.
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getHeight
public int getHeight()- Returns:
- The height of the bitmap.
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getBlackRow
Converts one row of luminance data to 1 bit data. May actually do the conversion, or return cached data. Callers should assume this method is expensive and call it as seldom as possible. This method is intended for decoding 1D barcodes and may choose to apply sharpening.- Parameters:
y
- The row to fetch, which must be in [0, bitmap height)row
- An optional preallocated array. If null or too small, it will be ignored. If used, the Binarizer will call BitArray.clear(). Always use the returned object.- Returns:
- The array of bits for this row (true means black).
- Throws:
NotFoundException
- if row can't be binarized
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getBlackMatrix
Converts a 2D array of luminance data to 1 bit. As above, assume this method is expensive and do not call it repeatedly. This method is intended for decoding 2D barcodes and may or may not apply sharpening. Therefore, a row from this matrix may not be identical to one fetched using getBlackRow(), so don't mix and match between them.- Returns:
- The 2D array of bits for the image (true means black).
- Throws:
NotFoundException
- if image can't be binarized to make a matrix
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isCropSupported
public boolean isCropSupported()- Returns:
- Whether this bitmap can be cropped.
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crop
Returns a new object with cropped image data. Implementations may keep a reference to the original data rather than a copy. Only callable if isCropSupported() is true.- Parameters:
left
- The left coordinate, which must be in [0,getWidth())top
- The top coordinate, which must be in [0,getHeight())width
- The width of the rectangle to crop.height
- The height of the rectangle to crop.- Returns:
- A cropped version of this object.
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isRotateSupported
public boolean isRotateSupported()- Returns:
- Whether this bitmap supports counter-clockwise rotation.
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rotateCounterClockwise
Returns a new object with rotated image data by 90 degrees counterclockwise. Only callable ifisRotateSupported()
is true.- Returns:
- A rotated version of this object.
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rotateCounterClockwise45
Returns a new object with rotated image data by 45 degrees counterclockwise. Only callable ifisRotateSupported()
is true.- Returns:
- A rotated version of this object.
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toString
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