Package com.google.zxing
Class PlanarYUVLuminanceSource
- java.lang.Object
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- com.google.zxing.LuminanceSource
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- com.google.zxing.PlanarYUVLuminanceSource
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public final class PlanarYUVLuminanceSource extends LuminanceSource
This object extends LuminanceSource around an array of YUV data returned from the camera driver, with the option to crop to a rectangle within the full data. This can be used to exclude superfluous pixels around the perimeter and speed up decoding. It works for any pixel format where the Y channel is planar and appears first, including YCbCr_420_SP and YCbCr_422_SP.
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Field Summary
Fields Modifier and Type Field Description private int
dataHeight
private int
dataWidth
private int
left
private static int
THUMBNAIL_SCALE_FACTOR
private int
top
private byte[]
yuvData
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Constructor Summary
Constructors Constructor Description PlanarYUVLuminanceSource(byte[] yuvData, int dataWidth, int dataHeight, int left, int top, int width, int height, boolean reverseHorizontal)
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Method Summary
All Methods Instance Methods Concrete Methods Modifier and Type Method Description LuminanceSource
crop(int left, int top, int width, int height)
Returns a new object with cropped image data.byte[]
getMatrix()
Fetches luminance data for the underlying bitmap.byte[]
getRow(int y, byte[] row)
Fetches one row of luminance data from the underlying platform's bitmap.int
getThumbnailHeight()
int
getThumbnailWidth()
boolean
isCropSupported()
int[]
renderThumbnail()
private void
reverseHorizontal(int width, int height)
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Methods inherited from class com.google.zxing.LuminanceSource
getHeight, getWidth, invert, isRotateSupported, rotateCounterClockwise, rotateCounterClockwise45, toString
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Field Detail
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THUMBNAIL_SCALE_FACTOR
private static final int THUMBNAIL_SCALE_FACTOR
- See Also:
- Constant Field Values
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yuvData
private final byte[] yuvData
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dataWidth
private final int dataWidth
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dataHeight
private final int dataHeight
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left
private final int left
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top
private final int top
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Method Detail
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getRow
public byte[] getRow(int y, byte[] row)
Description copied from class:LuminanceSource
Fetches one row of luminance data from the underlying platform's bitmap. Values range from 0 (black) to 255 (white). Because Java does not have an unsigned byte type, callers will have to bitwise and with 0xff for each value. It is preferable for implementations of this method to only fetch this row rather than the whole image, since no 2D Readers may be installed and getMatrix() may never be called.- Specified by:
getRow
in classLuminanceSource
- Parameters:
y
- The row to fetch, which must be in [0,getHeight())row
- An optional preallocated array. If null or too small, it will be ignored. Always use the returned object, and ignore the .length of the array.- Returns:
- An array containing the luminance data.
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getMatrix
public byte[] getMatrix()
Description copied from class:LuminanceSource
Fetches luminance data for the underlying bitmap. Values should be fetched using:int luminance = array[y * width + x] & 0xff
- Specified by:
getMatrix
in classLuminanceSource
- Returns:
- A row-major 2D array of luminance values. Do not use result.length as it may be larger than width * height bytes on some platforms. Do not modify the contents of the result.
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isCropSupported
public boolean isCropSupported()
- Overrides:
isCropSupported
in classLuminanceSource
- Returns:
- Whether this subclass supports cropping.
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crop
public LuminanceSource crop(int left, int top, int width, int height)
Description copied from class:LuminanceSource
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.- Overrides:
crop
in classLuminanceSource
- 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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renderThumbnail
public int[] renderThumbnail()
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getThumbnailWidth
public int getThumbnailWidth()
- Returns:
- width of image from
renderThumbnail()
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getThumbnailHeight
public int getThumbnailHeight()
- Returns:
- height of image from
renderThumbnail()
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reverseHorizontal
private void reverseHorizontal(int width, int height)
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