com.google.zxing.client.j2se
Class BufferedImageLuminanceSource

java.lang.Object
  extended by com.google.zxing.LuminanceSource
      extended by com.google.zxing.client.j2se.BufferedImageLuminanceSource

public final class BufferedImageLuminanceSource
extends LuminanceSource

This LuminanceSource implementation is meant for J2SE clients and our blackbox unit tests.

Author:
dswitkin@google.com (Daniel Switkin), Sean Owen, code@elektrowolle.de (Wolfgang Jung)

Constructor Summary
BufferedImageLuminanceSource(java.awt.image.BufferedImage image)
           
BufferedImageLuminanceSource(java.awt.image.BufferedImage image, int left, int top, int width, int height)
           
 
Method Summary
 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.
 boolean isCropSupported()
           
 boolean isRotateSupported()
          This is always true, since the image is a gray-scale image.
 LuminanceSource rotateCounterClockwise()
          Returns a new object with rotated image data.
 
Methods inherited from class com.google.zxing.LuminanceSource
getHeight, getWidth, toString
 
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait
 

Constructor Detail

BufferedImageLuminanceSource

public BufferedImageLuminanceSource(java.awt.image.BufferedImage image)

BufferedImageLuminanceSource

public BufferedImageLuminanceSource(java.awt.image.BufferedImage image,
                                    int left,
                                    int top,
                                    int width,
                                    int height)
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.

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 class LuminanceSource
Parameters:
left - The left coordinate, 0 <= left < getWidth().
top - The top coordinate, 0 <= top <= getHeight().
width - The width of the rectangle to crop.
height - The height of the rectangle to crop.
Returns:
A cropped version of this object.

isRotateSupported

public boolean isRotateSupported()
This is always true, since the image is a gray-scale image.

Overrides:
isRotateSupported in class LuminanceSource
Returns:
true

rotateCounterClockwise

public LuminanceSource rotateCounterClockwise()
Description copied from class: LuminanceSource
Returns a new object with rotated image data. Only callable if isRotateSupported() is true.

Overrides:
rotateCounterClockwise in class LuminanceSource
Returns:
A rotated version of this object.