com.google.zxing

Class RGBLuminanceSource

java.lang.Object

com.google.zxing.LuminanceSource

com.google.zxing.RGBLuminanceSource

public final class RGBLuminanceSource
extends LuminanceSource

This class is used to help decode images from files which arrive as RGB data from an ARGB pixel array. It does not support rotation.

Author:

dswitkin@google.com (Daniel Switkin), Betaminos

Constructor Summary

Constructors

Constructor and Description
RGBLuminanceSource(int width, int height, int[] pixels)

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.
boolean	isCropSupported()

Methods inherited from class com.google.zxing.LuminanceSource

getHeight, getWidth, invert, isRotateSupported, rotateCounterClockwise, rotateCounterClockwise45, toString

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Constructor Detail

RGBLuminanceSource

public RGBLuminanceSource(int width,
                          int height,
                          int[] pixels)

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.