com.google.zxing.common

类 GridSampler

java.lang.Object

com.google.zxing.common.GridSampler

直接已知子类:

DefaultGridSampler

public abstract class GridSampler
extends java.lang.Object

Implementations of this class can, given locations of finder patterns for a QR code in an image, sample the right points in the image to reconstruct the QR code, accounting for perspective distortion. It is abstracted since it is relatively expensive and should be allowed to take advantage of platform-specific optimized implementations, like Sun's Java Advanced Imaging library, but which may not be available in other environments such as J2ME, and vice versa. The implementation used can be controlled by calling setGridSampler(GridSampler) with an instance of a class which implements this interface.

作者:

Sean Owen

构造器概要

构造器

构造器和说明
GridSampler()

方法概要

限定符和类型	方法和说明
static GridSampler	getInstance()
abstract BitMatrix	sampleGrid(BitMatrix image, int dimensionX, int dimensionY, float p1ToX, float p1ToY, float p2ToX, float p2ToY, float p3ToX, float p3ToY, float p4ToX, float p4ToY, float p1FromX, float p1FromY, float p2FromX, float p2FromY, float p3FromX, float p3FromY, float p4FromX, float p4FromY) Samples an image for a rectangular matrix of bits of the given dimension.
abstract BitMatrix	sampleGrid(BitMatrix image, int dimensionX, int dimensionY, PerspectiveTransform transform)
static void	setGridSampler(GridSampler newGridSampler) Sets the implementation of GridSampler used by the library.

从类继承的方法 java.lang.Object

equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

构造器详细资料

GridSampler

public GridSampler()

方法详细资料

setGridSampler

public static void setGridSampler(GridSampler newGridSampler)

Sets the implementation of GridSampler used by the library. One global instance is stored, which may sound problematic. But, the implementation provided ought to be appropriate for the entire platform, and all uses of this library in the whole lifetime of the JVM. For instance, an Android activity can swap in an implementation that takes advantage of native platform libraries.

参数:

newGridSampler - The platform-specific object to install.

getInstance

public static GridSampler getInstance()

返回:

the current implementation of GridSampler

sampleGrid

public abstract BitMatrix sampleGrid(BitMatrix image,
                                     int dimensionX,
                                     int dimensionY,
                                     float p1ToX,
                                     float p1ToY,
                                     float p2ToX,
                                     float p2ToY,
                                     float p3ToX,
                                     float p3ToY,
                                     float p4ToX,
                                     float p4ToY,
                                     float p1FromX,
                                     float p1FromY,
                                     float p2FromX,
                                     float p2FromY,
                                     float p3FromX,
                                     float p3FromY,
                                     float p4FromX,
                                     float p4FromY)
                              throws NotFoundException

Samples an image for a rectangular matrix of bits of the given dimension. The sampling transformation is determined by the coordinates of 4 points, in the original and transformed image space.

参数:

image - image to sample

dimensionX - width of BitMatrix to sample from image

dimensionY - height of BitMatrix to sample from image

p1ToX - point 1 preimage X

p1ToY - point 1 preimage Y

p2ToX - point 2 preimage X

p2ToY - point 2 preimage Y

p3ToX - point 3 preimage X

p3ToY - point 3 preimage Y

p4ToX - point 4 preimage X

p4ToY - point 4 preimage Y

p1FromX - point 1 image X

p1FromY - point 1 image Y

p2FromX - point 2 image X

p2FromY - point 2 image Y

p3FromX - point 3 image X

p3FromY - point 3 image Y

p4FromX - point 4 image X

p4FromY - point 4 image Y

返回:

BitMatrix representing a grid of points sampled from the image within a region defined by the "from" parameters

抛出:

NotFoundException - if image can't be sampled, for example, if the transformation defined by the given points is invalid or results in sampling outside the image boundaries

sampleGrid

public abstract BitMatrix sampleGrid(BitMatrix image,
                                     int dimensionX,
                                     int dimensionY,
                                     PerspectiveTransform transform)
                              throws NotFoundException

抛出:

NotFoundException