docs/apidocs/com/google/zxing/qrcode/detector/FinderPatternFinder.html
Package com.google.zxing.qrcode.detector
java.lang.Object com.google.zxing.qrcode.detector.FinderPatternFinder
Direct Known Subclasses:MultiFinderPatternFinder
public class FinderPatternFinderextends Object
This class attempts to find finder patterns in a QR Code. Finder patterns are the square markers at three corners of a QR Code.
This class is thread-safe but not reentrant. Each thread must allocate its own object.
Fields
Modifier and Type
Field
Description
protected static final int
MAX_MODULES
protected static final int
MIN_SKIP
Constructors
Constructor
Description
FinderPatternFinder(BitMatrix image)
Creates a finder that will search the image for three finder patterns.
FinderPatternFinder(BitMatrix image, ResultPointCallback resultPointCallback)
All MethodsStatic MethodsInstance MethodsConcrete MethodsDeprecated Methods
Modifier and Type
Method
Description
protected final void
clearCounts(int[] counts)
Deprecated.
protected static void
doClearCounts(int[] counts)
protected static void
doShiftCounts2(int[] stateCount)
protected static boolean
foundPatternCross(int[] stateCount)
protected static boolean
foundPatternDiagonal(int[] stateCount)
protected final BitMatrix
getImage()
protected final List<FinderPattern>
getPossibleCenters()
protected final boolean
handlePossibleCenter(int[] stateCount, int i, int j)
This is called when a horizontal scan finds a possible alignment pattern.
protected final boolean
handlePossibleCenter(int[] stateCount, int i, int j, boolean pureBarcode)
Deprecated. only exists for backwards compatibility
protected final void
shiftCounts2(int[] stateCount)
Deprecated.
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
protected static final int MIN_SKIP See Also: - Constant Field Values
protected static final int MAX_MODULES See Also: - Constant Field Values
public FinderPatternFinder(BitMatrix image)
Creates a finder that will search the image for three finder patterns.
image - image to searchpublic FinderPatternFinder(BitMatrix image, ResultPointCallback resultPointCallback)
stateCount - count of black/white/black/white/black pixels just readReturns:true iff the proportions of the counts is close enough to the 1/1/3/1/1 ratios used by finder patterns to be considered a matchstateCount - count of black/white/black/white/black pixels just readReturns:true iff the proportions of the counts is close enough to the 1/1/3/1/1 ratios used by finder patterns to be considered a match@Deprecated protected final void clearCounts(int[] counts)
@Deprecated protected final void shiftCounts2(int[] stateCount)
@Deprecated protected final boolean handlePossibleCenter(int[] stateCount, int i, int j, boolean pureBarcode)
Deprecated. only exists for backwards compatibility
Parameters:stateCount - reading state module counts from horizontal scani - row where finder pattern may be foundj - end of possible finder pattern in rowpureBarcode - ignoredReturns:true if a finder pattern candidate was found this timeSee Also:
- handlePossibleCenter(int[], int, int)
protected final boolean handlePossibleCenter(int[] stateCount, int i, int j)
This is called when a horizontal scan finds a possible alignment pattern. It will cross check with a vertical scan, and if successful, will, ah, cross-cross-check with another horizontal scan. This is needed primarily to locate the real horizontal center of the pattern in cases of extreme skew. And then we cross-cross-cross check with another diagonal scan.
If that succeeds the finder pattern location is added to a list that tracks the number of times each location has been nearly-matched as a finder pattern. Each additional find is more evidence that the location is in fact a finder pattern center
Parameters:stateCount - reading state module counts from horizontal scani - row where finder pattern may be foundj - end of possible finder pattern in rowReturns:true if a finder pattern candidate was found this time