import DecodeHintType from '../../DecodeHintType';
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import ResultPointCallback from '../../ResultPointCallback';
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import BitMatrix from '../../common/BitMatrix';
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import FinderPattern from './FinderPattern';
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import FinderPatternInfo from './FinderPatternInfo';
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/**
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* <p>This class attempts to find finder patterns in a QR Code. Finder patterns are the square
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* markers at three corners of a QR Code.</p>
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*
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* <p>This class is thread-safe but not reentrant. Each thread must allocate its own object.
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*
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* @author Sean Owen
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*/
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export default class FinderPatternFinder {
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private image;
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private resultPointCallback;
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private static CENTER_QUORUM;
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protected static MIN_SKIP: number;
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protected static MAX_MODULES: number;
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private possibleCenters;
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private hasSkipped;
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private crossCheckStateCount;
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/**
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* <p>Creates a finder that will search the image for three finder patterns.</p>
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*
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* @param image image to search
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*/
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constructor(image: BitMatrix, resultPointCallback: ResultPointCallback);
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protected getImage(): BitMatrix;
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protected getPossibleCenters(): FinderPattern[];
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find(hints: Map<DecodeHintType, any>): FinderPatternInfo;
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/**
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* Given a count of black/white/black/white/black pixels just seen and an end position,
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* figures the location of the center of this run.
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*/
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private static centerFromEnd;
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/**
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* @param stateCount count of black/white/black/white/black pixels just read
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* @return true iff the proportions of the counts is close enough to the 1/1/3/1/1 ratios
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* used by finder patterns to be considered a match
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*/
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protected static foundPatternCross(stateCount: Int32Array): boolean;
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private getCrossCheckStateCount;
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/**
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* After a vertical and horizontal scan finds a potential finder pattern, this method
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* "cross-cross-cross-checks" by scanning down diagonally through the center of the possible
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* finder pattern to see if the same proportion is detected.
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*
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* @param startI row where a finder pattern was detected
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* @param centerJ center of the section that appears to cross a finder pattern
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* @param maxCount maximum reasonable number of modules that should be
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* observed in any reading state, based on the results of the horizontal scan
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* @param originalStateCountTotal The original state count total.
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* @return true if proportions are withing expected limits
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*/
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private crossCheckDiagonal;
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/**
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* <p>After a horizontal scan finds a potential finder pattern, this method
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* "cross-checks" by scanning down vertically through the center of the possible
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* finder pattern to see if the same proportion is detected.</p>
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*
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* @param startI row where a finder pattern was detected
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* @param centerJ center of the section that appears to cross a finder pattern
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* @param maxCount maximum reasonable number of modules that should be
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* observed in any reading state, based on the results of the horizontal scan
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* @return vertical center of finder pattern, or {@link Float#NaN} if not found
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*/
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private crossCheckVertical;
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/**
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* <p>Like {@link #crossCheckVertical(int, int, int, int)}, and in fact is basically identical,
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* except it reads horizontally instead of vertically. This is used to cross-cross
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* check a vertical cross check and locate the real center of the alignment pattern.</p>
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*/
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private crossCheckHorizontal;
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/**
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* <p>This is called when a horizontal scan finds a possible alignment pattern. It will
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* cross check with a vertical scan, and if successful, will, ah, cross-cross-check
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* with another horizontal scan. This is needed primarily to locate the real horizontal
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* center of the pattern in cases of extreme skew.
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* And then we cross-cross-cross check with another diagonal scan.</p>
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*
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* <p>If that succeeds the finder pattern location is added to a list that tracks
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* the number of times each location has been nearly-matched as a finder pattern.
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* Each additional find is more evidence that the location is in fact a finder
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* pattern center
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*
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* @param stateCount reading state module counts from horizontal scan
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* @param i row where finder pattern may be found
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* @param j end of possible finder pattern in row
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* @param pureBarcode true if in "pure barcode" mode
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* @return true if a finder pattern candidate was found this time
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*/
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protected handlePossibleCenter(stateCount: Int32Array, i: number, j: number, pureBarcode: boolean): boolean;
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/**
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* @return number of rows we could safely skip during scanning, based on the first
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* two finder patterns that have been located. In some cases their position will
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* allow us to infer that the third pattern must lie below a certain point farther
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* down in the image.
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*/
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private findRowSkip;
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/**
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* @return true iff we have found at least 3 finder patterns that have been detected
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* at least {@link #CENTER_QUORUM} times each, and, the estimated module size of the
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* candidates is "pretty similar"
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*/
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private haveMultiplyConfirmedCenters;
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/**
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* @return the 3 best {@link FinderPattern}s from our list of candidates. The "best" are
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* those that have been detected at least {@link #CENTER_QUORUM} times, and whose module
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* size differs from the average among those patterns the least
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* @throws NotFoundException if 3 such finder patterns do not exist
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*/
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private selectBestPatterns;
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}
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