com.google.zxing

Class InvertedLuminanceSource

java.lang.Object

com.google.zxing.LuminanceSource

com.google.zxing.InvertedLuminanceSource

public final class InvertedLuminanceSource
extends LuminanceSource

A wrapper implementation of LuminanceSource which inverts the luminances it returns -- black becomes white and vice versa, and each value becomes (255-value).

Author:

Sean Owen

Constructor Summary

Constructors

Constructor and Description
InvertedLuminanceSource(LuminanceSource delegate)

Method Summary

Modifier and Type	Method and 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.
LuminanceSource	invert()
boolean	isCropSupported()
boolean	isRotateSupported()
LuminanceSource	rotateCounterClockwise() Returns a new object with rotated image data by 90 degrees counterclockwise.
LuminanceSource	rotateCounterClockwise45() Returns a new object with rotated image data by 45 degrees counterclockwise.

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

InvertedLuminanceSource

public InvertedLuminanceSource(LuminanceSource delegate)

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, 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.

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, 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.

isRotateSupported

public boolean isRotateSupported()

Overrides:

isRotateSupported in class LuminanceSource

Returns:

Whether this subclass supports counter-clockwise rotation.

invert

public LuminanceSource invert()

Overrides:

invert in class LuminanceSource

Returns:

original delegate LuminanceSource since invert undoes itself

rotateCounterClockwise

public LuminanceSource rotateCounterClockwise()

Description copied from class: LuminanceSource

Returns a new object with rotated image data by 90 degrees counterclockwise. Only callable if LuminanceSource.isRotateSupported() is true.

Overrides:

rotateCounterClockwise in class LuminanceSource

Returns:

A rotated version of this object.

rotateCounterClockwise45

public LuminanceSource rotateCounterClockwise45()

Description copied from class: LuminanceSource

Returns a new object with rotated image data by 45 degrees counterclockwise. Only callable if LuminanceSource.isRotateSupported() is true.

Overrides:

rotateCounterClockwise45 in class LuminanceSource

Returns:

A rotated version of this object.