Merge pull request #2929 from SUSTech-OpenCV:bugfix-barcode

Bugfix: barcode module

* bugfix:
1. jni crashing while coping vector<BarcodeType> to list;
2. in python/java, assertion fails when calling decode(), because of (2D Mat).copyTo(vector<Point>);
3. the algorithm of decodeROI() is wrong.

* add python and java tests

* use constexpr

Author: darkliang

modules/barcode/misc/java/src/cpp/barcode_converters.cpp

@@ -16,8 +16,8 @@ void Copy_vector_BarcodeType_to_List(JNIEnv* env, std::vector<cv::barcode::Barco
     jmethodID m_clear = LIST_CLEAR(env, juArrayList);
     env->CallVoidMethod(list, m_clear);
 
-    static jclass jInteger = env->FindClass("java/lang/Integer");
-    static jmethodID m_create_Integer = env->GetMethodID(jInteger, "<init>", "(I)V");
+    jclass jInteger = env->FindClass("java/lang/Integer");
+    jmethodID m_create_Integer = CONSTRUCTOR(env, jInteger);
 
     for (size_t i = 0; i < vs.size(); ++i)
     {

modules/barcode/misc/java/test/BarcodeDetectorTest.java

@@ -0,0 +1,51 @@
+package org.opencv.test.barcode;
+
+import java.util.List;
+import org.opencv.core.Mat;
+import org.opencv.barcode.BarcodeDetector;
+import org.opencv.imgcodecs.Imgcodecs;
+import org.opencv.test.OpenCVTestCase;
+import java.util.ArrayList;
+import static org.opencv.barcode.Barcode.EAN_13;
+
+public class BarcodeDetectorTest extends OpenCVTestCase {
+
+    private final static String ENV_OPENCV_TEST_DATA_PATH = "OPENCV_TEST_DATA_PATH";
+    private String testDataPath;
+
+    @Override
+    protected void setUp() throws Exception {
+        super.setUp();
+
+        testDataPath = System.getenv(ENV_OPENCV_TEST_DATA_PATH);
+        if (testDataPath == null)
+            throw new Exception(ENV_OPENCV_TEST_DATA_PATH + " has to be defined!");
+    }
+
+    public void testDetectAndDecode() {
+        Mat img = Imgcodecs.imread(testDataPath + "/cv/barcode/multiple/4_barcodes.jpg");
+        assertFalse(img.empty());
+        BarcodeDetector detector = new BarcodeDetector();
+        assertNotNull(detector);
+        List < String > infos = new ArrayList< String >();
+        List < Integer > types = new ArrayList< Integer >();
+
+        boolean result = detector.detectAndDecode(img, infos, types);
+        assertTrue(result);
+        assertEquals(infos.size(), 4);
+        assertEquals(types.size(), 4);
+        final String[]  correctResults = {"9787122276124", "9787118081473", "9787564350840", "9783319200064"};
+        for (int i = 0; i < 4; i++) {
+            assertEquals(types.get(i).intValue(), EAN_13);
+            result = false;
+            for (int j = 0; j < 4; j++) {
+                if (correctResults[j].equals(infos.get(i))) {
+                    result = true;
+                    break;
+                }
+            }
+            assertTrue(result);
+        }
+
+    }
+}

modules/barcode/misc/python/test/test_barcode_detector.py

@@ -0,0 +1,30 @@
+#!/usr/bin/env python
+'''
+===============================================================================
+Barcode detect and decode pipeline.
+===============================================================================
+'''
+import os
+import numpy as np
+import cv2 as cv
+
+from tests_common import NewOpenCVTests
+
+class barcode_detector_test(NewOpenCVTests):
+
+    def test_detect(self):
+        img = cv.imread(os.path.join(self.extraTestDataPath, 'cv/barcode/multiple/4_barcodes.jpg'))
+        self.assertFalse(img is None)
+        detector = cv.barcode_BarcodeDetector()
+        retval, corners = detector.detect(img)
+        self.assertTrue(retval)
+        self.assertEqual(corners.shape, (4, 4, 2))
+
+    def test_detect_and_decode(self):
+        img = cv.imread(os.path.join(self.extraTestDataPath, 'cv/barcode/single/book.jpg'))
+        self.assertFalse(img is None)
+        detector = cv.barcode_BarcodeDetector()
+        retval, decoded_info, decoded_type, corners = detector.detectAndDecode(img)
+        self.assertEqual(decoded_info[0], "9787115279460")
+        self.assertEqual(decoded_type[0], cv.barcode.EAN_13)
+        self.assertEqual(corners.shape, (1, 4, 2))

modules/barcode/src/barcode.cpp

@@ -130,30 +130,17 @@ struct BarcodeDetector::Impl
 
     ~Impl() = default;
 
-    vector<Mat> initDecode(const Mat &src, const vector<Point2f> &points) const;
+    vector<Mat> initDecode(const Mat &src, const vector<vector<Point2f>> &points) const;
 
     std::shared_ptr<SuperScale> sr;
     bool use_nn_sr = false;
 };
 
 // return cropped and scaled bar img
-vector<Mat> BarcodeDetector::Impl::initDecode(const Mat &src, const vector<Point2f> &points) const
+vector<Mat> BarcodeDetector::Impl::initDecode(const Mat &src, const vector<vector<Point2f>> &points) const
 {
-    vector<vector<Point2f>> src_points;
-    CV_Assert(!points.empty());
-    CV_Assert((points.size() % 4) == 0);
-    src_points.clear();
-    for (int i = 0; (uint) i < points.size(); i += 4)
-    {
-        vector<Point2f> tempMat{points.cbegin() + i, points.cbegin() + i + 4};
-        if (contourArea(tempMat) > 0.0)
-        {
-            src_points.push_back(tempMat);
-        }
-    }
-    CV_Assert(!src_points.empty());
     vector<Mat> bar_imgs;
-    for (auto &corners : src_points)
+    for (auto &corners : points)
     {
         Mat bar_img;
         cropROI(src, bar_img, corners);
@@ -224,8 +211,18 @@ bool BarcodeDetector::decode(InputArray img, InputArray points, vector<std::stri
     }
     CV_Assert(points.size().width > 0);
     CV_Assert((points.size().width % 4) == 0);
-    vector<Point2f> src_points;
-    points.copyTo(src_points);
+    vector<vector<Point2f>> src_points;
+    Mat bar_points = points.getMat();
+    bar_points = bar_points.reshape(2, 1);
+    for (int i = 0; i < bar_points.size().width; i += 4)
+    {
+        vector<Point2f> tempMat = bar_points.colRange(i, i + 4);
+        if (contourArea(tempMat) > 0.0)
+        {
+            src_points.push_back(tempMat);
+        }
+    }
+    CV_Assert(!src_points.empty());
     vector<Mat> bar_imgs = p->initDecode(inarr, src_points);
     BarDecode bardec;
     bardec.init(bar_imgs);

modules/barcode/src/decoder/abs_decoder.cpp

@@ -73,7 +73,7 @@ patternMatchVariance(const Counter &counter, const std::vector<int> &pattern, ui
         // If we don't even have one pixel per unit of bar width, assume this is too small
         // to reliably match, so fail:
         // and use constexpr functions
-        return std::numeric_limits<uint>::max();// max
+        return WHITE;// max
     }
     // We're going to fake floating-point math in integers. We just need to use more bits.
     // Scale up patternLength so that intermediate values below like scaledCounter will have
@@ -89,7 +89,7 @@ patternMatchVariance(const Counter &counter, const std::vector<int> &pattern, ui
         uint variance = std::abs(cnt - scaledPattern);
         if (variance > maxIndividualVariance)
         {
-            return std::numeric_limits<uint>::max();
+            return WHITE;
         }
         totalVariance += variance;
     }

modules/barcode/src/decoder/abs_decoder.hpp

@@ -12,9 +12,9 @@ namespace cv {
 namespace barcode {
 using std::string;
 using std::vector;
-constexpr static int BLACK = std::numeric_limits<uchar>::min();
+constexpr static uchar BLACK = std::numeric_limits<uchar>::min();
 // WHITE elemental area is 0xff
-constexpr static int WHITE = std::numeric_limits<uchar>::max();
+constexpr static uchar WHITE = std::numeric_limits<uchar>::max();
 
 
 struct Result

modules/barcode/src/decoder/upcean_decoder.cpp

@@ -145,11 +145,17 @@ std::pair<Result, float> UPCEANDecoder::decodeROI(const Mat &bar_img) const
     std::string max_result;
     BarcodeType max_type = BarcodeType::NONE;
 
-    int step = bar_img.rows / (DIVIDE_PART + BIAS_PART);
+    const int step = bar_img.rows / (DIVIDE_PART + BIAS_PART);
     Result result;
+    int row_num;
     for (int i = 0; i < DIVIDE_PART; ++i)
     {
-        const auto *ptr = bar_img.ptr<uchar>(i * step);
+        row_num = (i + BIAS_PART / 2) * step;
+        if (row_num < 0 || row_num > bar_img.rows)
+        {
+            continue;
+        }
+        const auto *ptr = bar_img.ptr<uchar>(row_num);
         vector<uchar> line(ptr, ptr + bar_img.cols);
         result = decodeLine(line);
         if (result.format != BarcodeType::NONE)
@@ -159,21 +165,17 @@ std::pair<Result, float> UPCEANDecoder::decodeROI(const Mat &bar_img) const
             if (result_vote[result.result] > vote_cnt)
             {
                 vote_cnt = result_vote[result.result];
-                if ((vote_cnt << 1) > total_vote)
-                {
-                    max_result = result.result;
-                    max_type = result.format;
-                }
+                max_result = result.result;
+                max_type = result.format;
             }
         }
     }
-
-    float confidence = 0;
-    if (total_vote != 0)
+    if (total_vote == 0 || (vote_cnt << 2) < total_vote)
     {
-        confidence = (float) vote_cnt / (float) total_vote;
+        return std::make_pair(Result(string(), BarcodeType::NONE), 0.0f);
     }
 
+    float confidence = (float) vote_cnt / (float) DIVIDE_PART;
     //Check if it is UPC-A format
     if (max_type == BarcodeType::EAN_13 && max_result[0] == '0')
     {

modules/barcode/src/detector/bardetect.cpp

@@ -131,7 +131,7 @@ bool Detect::computeTransformationPoints()
 void Detect::preprocess()
 {
     Mat scharr_x, scharr_y, temp;
-    static constexpr double THRESHOLD_MAGNITUDE = 56.;
+    static constexpr double THRESHOLD_MAGNITUDE = 64.;
     Scharr(resized_barcode, scharr_x, CV_32F, 1, 0);
     Scharr(resized_barcode, scharr_y, CV_32F, 0, 1);
     // calculate magnitude of gradient and truncate