com.google.zxing.client.android
Class PlanarYUVLuminanceSource

java.lang.Object
  extended by com.google.zxing.LuminanceSource
      extended by com.google.zxing.client.android.PlanarYUVLuminanceSource

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.

Author:
dswitkin@google.com (Daniel Switkin)

Constructor Summary
PlanarYUVLuminanceSource(byte[] yuvData, int dataWidth, int dataHeight, int left, int top, int width, int height, boolean reverseHorizontal)
           
 
Method Summary
 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.
 boolean isCropSupported()
           
 android.graphics.Bitmap renderCroppedGreyscaleBitmap()
           
 
Methods inherited from class com.google.zxing.LuminanceSource
crop, getHeight, getWidth, isRotateSupported, rotateCounterClockwise, toString
 
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait
 

Constructor Detail

PlanarYUVLuminanceSource

public PlanarYUVLuminanceSource(byte[] yuvData,
                                int dataWidth,
                                int dataHeight,
                                int left,
                                int top,
                                int width,
                                int height,
                                boolean reverseHorizontal)
Method Detail

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 class LuminanceSource
Parameters:
y - The row to fetch, 0 <= y < 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.

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 class LuminanceSource
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.

isCropSupported

public boolean isCropSupported()
Overrides:
isCropSupported in class LuminanceSource
Returns:
Whether this subclass supports cropping.

renderCroppedGreyscaleBitmap

public android.graphics.Bitmap renderCroppedGreyscaleBitmap()