QRCodeReader.php

<?php
/*
 * Copyright 2007 ZXing authors
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

namespace Zxing\Qrcode;

use Zxing\BinaryBitmap;
use Zxing\ChecksumException;
use Zxing\FormatException;
use Zxing\NotFoundException;
use Zxing\Reader;
use Zxing\Result;
use Zxing\Common\BitMatrix;
use Zxing\Qrcode\Decoder\Decoder;
use Zxing\Qrcode\Detector\Detector;

/**
 * This implementation can detect and decode QR Codes in an image.
 *
 * @author Sean Owen
 */
class QRCodeReader implements Reader
{
    private static $NO_POINTS = [];
    private $decoder;

    public function __construct()
    {
        $this->decoder = new Decoder();
    }

    /**
     * @param BinaryBitmap $image
     * @param null         $hints
     *
     * @return Result
     * @throws \Zxing\FormatException
     * @throws \Zxing\NotFoundException
     */
    public function decode(BinaryBitmap $image, $hints = null)
    {
        $decoderResult = null;
        if ($hints !== null && $hints['PURE_BARCODE']) {
            $bits          = self::extractPureBits($image->getBlackMatrix());
            $decoderResult = $this->decoder->decode($bits, $hints);
            $points        = self::$NO_POINTS;
        } else {
            $detector       = new Detector($image->getBlackMatrix());
            $detectorResult = $detector->detect($hints);

            $decoderResult = $this->decoder->decode($detectorResult->getBits(), $hints);
            $points        = $detectorResult->getPoints();
        }
        $result = new Result($decoderResult->getText(), $decoderResult->getRawBytes(), $points, 'QR_CODE');//BarcodeFormat.QR_CODE

        $byteSegments = $decoderResult->getByteSegments();
        if ($byteSegments !== null) {
            $result->putMetadata('BYTE_SEGMENTS', $byteSegments);//ResultMetadataType.BYTE_SEGMENTS
        }
        $ecLevel = $decoderResult->getECLevel();
        if ($ecLevel !== null) {
            $result->putMetadata('ERROR_CORRECTION_LEVEL', $ecLevel);//ResultMetadataType.ERROR_CORRECTION_LEVEL
        }
        if ($decoderResult->hasStructuredAppend()) {
            $result->putMetadata(
                'STRUCTURED_APPEND_SEQUENCE',//ResultMetadataType.STRUCTURED_APPEND_SEQUENCE
                $decoderResult->getStructuredAppendSequenceNumber()
            );
            $result->putMetadata(
                'STRUCTURED_APPEND_PARITY',//ResultMetadataType.STRUCTURED_APPEND_PARITY
                $decoderResult->getStructuredAppendParity()
            );
        }

        return $result;
    }

    /**
     * Locates and decodes a QR code in an image.
     *
     * @return a String representing the content encoded by the QR code
     * @throws NotFoundException if a QR code cannot be found
     * @throws FormatException if a QR code cannot be decoded
     * @throws ChecksumException if error correction fails
     */

    /**
     * This method detects a code in a "pure" image -- that is, pure monochrome image
     * which contains only an unrotated, unskewed, image of a code, with some white border
     * around it. This is a specialized method that works exceptionally fast in this special
     * case.
     *
     * @see com.google.zxing.datamatrix.DataMatrixReader#extractPureBits(BitMatrix)
     */
    private static function extractPureBits(BitMatrix $image)
    {
        $leftTopBlack     = $image->getTopLeftOnBit();
        $rightBottomBlack = $image->getBottomRightOnBit();
        if ($leftTopBlack === null || $rightBottomBlack == null) {
            throw NotFoundException::getNotFoundInstance();
        }

        $moduleSize = self::moduleSize($leftTopBlack, $image);

        $top    = $leftTopBlack[1];
        $bottom = $rightBottomBlack[1];
        $left   = $leftTopBlack[0];
        $right  = $rightBottomBlack[0];

        // Sanity check!
        if ($left >= $right || $top >= $bottom) {
            throw NotFoundException::getNotFoundInstance();
        }

        if ($bottom - $top != $right - $left) {
            // Special case, where bottom-right module wasn't black so we found something else in the last row
            // Assume it's a square, so use height as the width
            $right = $left + ($bottom - $top);
        }

        $matrixWidth  = round(($right - $left + 1) / $moduleSize);
        $matrixHeight = round(($bottom - $top + 1) / $moduleSize);
        if ($matrixWidth <= 0 || $matrixHeight <= 0) {
            throw NotFoundException::getNotFoundInstance();
        }
        if ($matrixHeight != $matrixWidth) {
            // Only possibly decode square regions
            throw NotFoundException::getNotFoundInstance();
        }

        // Push in the "border" by half the module width so that we start
        // sampling in the middle of the module. Just in case the image is a
        // little off, this will help recover.
        $nudge = (int)($moduleSize / 2.0);// $nudge = (int) ($moduleSize / 2.0f);
        $top   += $nudge;
        $left  += $nudge;

        // But careful that this does not sample off the edge
        // "right" is the farthest-right valid pixel location -- right+1 is not necessarily
        // This is positive by how much the inner x loop below would be too large
        $nudgedTooFarRight = $left + (int)(($matrixWidth - 1) * $moduleSize) - $right;
        if ($nudgedTooFarRight > 0) {
            if ($nudgedTooFarRight > $nudge) {
                // Neither way fits; abort
                throw NotFoundException::getNotFoundInstance();
            }
            $left -= $nudgedTooFarRight;
        }
        // See logic above
        $nudgedTooFarDown = $top + (int)(($matrixHeight - 1) * $moduleSize) - $bottom;
        if ($nudgedTooFarDown > 0) {
            if ($nudgedTooFarDown > $nudge) {
                // Neither way fits; abort
                throw NotFoundException::getNotFoundInstance();
            }
            $top -= $nudgedTooFarDown;
        }

        // Now just read off the bits
        $bits = new BitMatrix($matrixWidth, $matrixHeight);
        for ($y = 0; $y < $matrixHeight; $y++) {
            $iOffset = $top + (int)($y * $moduleSize);
            for ($x = 0; $x < $matrixWidth; $x++) {
                if ($image->get($left + (int)($x * $moduleSize), $iOffset)) {
                    $bits->set($x, $y);
                }
            }
        }

        return $bits;
    }

    private static function moduleSize($leftTopBlack, BitMatrix $image)
    {
        $height = $image->getHeight();
        $width  = $image->getWidth();
        $x           = $leftTopBlack[0];
        $y           = $leftTopBlack[1];
        /*$x           = $leftTopBlack[0];
        $y           = $leftTopBlack[1];*/
        $inBlack     = true;
        $transitions = 0;
        while ($x < $width && $y < $height) {
            if ($inBlack != $image->get($x, $y)) {
                if (++$transitions == 5) {
                    break;
                }
                $inBlack = !$inBlack;
            }
            $x++;
            $y++;
        }
        if ($x == $width || $y == $height) {
            throw NotFoundException::getNotFoundInstance();
        }

        return ($x - $leftTopBlack[0]) / 7.0; //return ($x - $leftTopBlack[0]) / 7.0f;
    }

    public function reset()
    {
        // do nothing
    }

    protected final function getDecoder()
    {
        return $this->decoder;
    }
}