Merge pull request #25703 from mshabunin:fix-imread-arg

asmorkalov · web-flow · commit 0d1ed49d2a12 · 2024-06-06T12:50:30.000+03:00
imgproc: fixed imread with output image argument
diff --git a/modules/imgcodecs/src/grfmt_hdr.cpp b/modules/imgcodecs/src/grfmt_hdr.cpp
@@ -93,10 +93,18 @@ bool HdrDecoder::readData(Mat& _img)
     RGBE_ReadPixels_RLE(file, const_cast<float*>(img.ptr<float>()), img.cols, img.rows);
     fclose(file); file = NULL;
 
-    if(_img.depth() == img.depth()) {
-        img.convertTo(_img, _img.type());
-    } else {
-        img.convertTo(_img, _img.type(), 255);
+    // NOTE: 'img' has type CV32FC3
+    switch (_img.depth())
+    {
+        case CV_8U: img.convertTo(img, _img.depth(), 255); break;
+        case CV_32F: break;
+        default: CV_Error(Error::StsError, "Wrong expected image depth, allowed: CV_8U and CV_32F");
+    }
+    switch (_img.channels())
+    {
+        case 1: cvtColor(img, _img, COLOR_BGR2GRAY); break;
+        case 3: img.copyTo(_img); break;
+        default: CV_Error(Error::StsError, "Wrong expected image channels, allowed: 1 and 3");
     }
     return true;
 }
diff --git a/modules/imgcodecs/src/loadsave.cpp b/modules/imgcodecs/src/loadsave.cpp
@@ -81,6 +81,22 @@ static Size validateInputImageSize(const Size& size)
 }
 
 
+static inline int calcType(int type, int flags)
+{
+    if( (flags & IMREAD_LOAD_GDAL) != IMREAD_LOAD_GDAL && flags != IMREAD_UNCHANGED )
+    {
+        if( (flags & IMREAD_ANYDEPTH) == 0 )
+            type = CV_MAKETYPE(CV_8U, CV_MAT_CN(type));
+
+        if( (flags & IMREAD_COLOR) != 0 ||
+           ((flags & IMREAD_ANYCOLOR) != 0 && CV_MAT_CN(type) > 1) )
+            type = CV_MAKETYPE(CV_MAT_DEPTH(type), 3);
+        else
+            type = CV_MAKETYPE(CV_MAT_DEPTH(type), 1);
+    }
+    return type;
+}
+
 namespace {
 
 class ByteStreamBuffer: public std::streambuf
@@ -328,7 +344,7 @@ static ImageEncoder findEncoder( const String& _ext )
 }
 
 
-static void ExifTransform(int orientation, Mat& img)
+static void ExifTransform(int orientation, OutputArray img)
 {
     switch( orientation )
     {
@@ -365,7 +381,7 @@ static void ExifTransform(int orientation, Mat& img)
     }
 }
 
-static void ApplyExifOrientation(ExifEntry_t orientationTag, Mat& img)
+static void ApplyExifOrientation(ExifEntry_t orientationTag, OutputArray img)
 {
     int orientation = IMAGE_ORIENTATION_TL;
 
@@ -385,7 +401,7 @@ static void ApplyExifOrientation(ExifEntry_t orientationTag, Mat& img)
  *
 */
 static bool
-imread_( const String& filename, int flags, Mat& mat )
+imread_( const String& filename, int flags, OutputArray mat )
 {
     /// Search for the relevant decoder to handle the imagery
     ImageDecoder decoder;
@@ -444,18 +460,7 @@ imread_( const String& filename, int flags, Mat& mat )
     Size size = validateInputImageSize(Size(decoder->width(), decoder->height()));
 
     // grab the decoded type
-    int type = decoder->type();
-    if( (flags & IMREAD_LOAD_GDAL) != IMREAD_LOAD_GDAL && flags != IMREAD_UNCHANGED )
-    {
-        if( (flags & IMREAD_ANYDEPTH) == 0 )
-            type = CV_MAKETYPE(CV_8U, CV_MAT_CN(type));
-
-        if( (flags & IMREAD_COLOR) != 0 ||
-           ((flags & IMREAD_ANYCOLOR) != 0 && CV_MAT_CN(type) > 1) )
-            type = CV_MAKETYPE(CV_MAT_DEPTH(type), 3);
-        else
-            type = CV_MAKETYPE(CV_MAT_DEPTH(type), 1);
-    }
+    const int type = calcType(decoder->type(), flags);
 
     if (mat.empty())
     {
@@ -469,11 +474,16 @@ imread_( const String& filename, int flags, Mat& mat )
     }
 
     // read the image data
+    Mat real_mat = mat.getMat();
+    const void * original_ptr = real_mat.data;
     bool success = false;
     try
     {
-        if (decoder->readData(mat))
+        if (decoder->readData(real_mat))
+        {
+            CV_CheckTrue(original_ptr == real_mat.data, "Internal imread issue");
             success = true;
+        }
     }
     catch (const cv::Exception& e)
     {
@@ -567,18 +577,7 @@ imreadmulti_(const String& filename, int flags, std::vector<Mat>& mats, int star
     while (current < count)
     {
         // grab the decoded type
-        int type = decoder->type();
-        if ((flags & IMREAD_LOAD_GDAL) != IMREAD_LOAD_GDAL && flags != IMREAD_UNCHANGED)
-        {
-            if ((flags & IMREAD_ANYDEPTH) == 0)
-                type = CV_MAKETYPE(CV_8U, CV_MAT_CN(type));
-
-            if ((flags & IMREAD_COLOR) != 0 ||
-                ((flags & IMREAD_ANYCOLOR) != 0 && CV_MAT_CN(type) > 1))
-                type = CV_MAKETYPE(CV_MAT_DEPTH(type), 3);
-            else
-                type = CV_MAKETYPE(CV_MAT_DEPTH(type), 1);
-        }
+        const int type = calcType(decoder->type(), flags);
 
         // established the required input image size
         Size size = validateInputImageSize(Size(decoder->width(), decoder->height()));
@@ -645,10 +644,8 @@ void imread( const String& filename, OutputArray dst, int flags )
 {
     CV_TRACE_FUNCTION();
 
-    Mat img = dst.getMat();
-
     /// load the data
-    imread_(filename, flags, img);
+    imread_(filename, flags, dst);
 }
 
 /**
@@ -884,18 +881,7 @@ imdecode_( const Mat& buf, int flags, Mat& mat )
     // established the required input image size
     Size size = validateInputImageSize(Size(decoder->width(), decoder->height()));
 
-    int type = decoder->type();
-    if( (flags & IMREAD_LOAD_GDAL) != IMREAD_LOAD_GDAL && flags != IMREAD_UNCHANGED )
-    {
-        if( (flags & IMREAD_ANYDEPTH) == 0 )
-            type = CV_MAKETYPE(CV_8U, CV_MAT_CN(type));
-
-        if( (flags & IMREAD_COLOR) != 0 ||
-           ((flags & IMREAD_ANYCOLOR) != 0 && CV_MAT_CN(type) > 1) )
-            type = CV_MAKETYPE(CV_MAT_DEPTH(type), 3);
-        else
-            type = CV_MAKETYPE(CV_MAT_DEPTH(type), 1);
-    }
+    const int type = calcType(decoder->type(), flags);
 
     mat.create( size.height, size.width, type );
 
@@ -1046,18 +1032,7 @@ imdecodemulti_(const Mat& buf, int flags, std::vector<Mat>& mats, int start, int
     while (current < count)
     {
         // grab the decoded type
-        int type = decoder->type();
-        if ((flags & IMREAD_LOAD_GDAL) != IMREAD_LOAD_GDAL && flags != IMREAD_UNCHANGED)
-        {
-            if ((flags & IMREAD_ANYDEPTH) == 0)
-                type = CV_MAKETYPE(CV_8U, CV_MAT_CN(type));
-
-            if ((flags & IMREAD_COLOR) != 0 ||
-                ((flags & IMREAD_ANYCOLOR) != 0 && CV_MAT_CN(type) > 1))
-                type = CV_MAKETYPE(CV_MAT_DEPTH(type), 3);
-            else
-                type = CV_MAKETYPE(CV_MAT_DEPTH(type), 1);
-        }
+        const int type = calcType(decoder->type(), flags);
 
         // established the required input image size
         Size size = validateInputImageSize(Size(decoder->width(), decoder->height()));
@@ -1316,17 +1291,7 @@ bool ImageCollection::Impl::readHeader() {
 
 // readHeader must be called before calling this method
 Mat ImageCollection::Impl::readData() {
-    int type = m_decoder->type();
-    if ((m_flags & IMREAD_LOAD_GDAL) != IMREAD_LOAD_GDAL && m_flags != IMREAD_UNCHANGED) {
-        if ((m_flags & IMREAD_ANYDEPTH) == 0)
-            type = CV_MAKETYPE(CV_8U, CV_MAT_CN(type));
-
-        if ((m_flags & IMREAD_COLOR) != 0 ||
-            ((m_flags & IMREAD_ANYCOLOR) != 0 && CV_MAT_CN(type) > 1))
-            type = CV_MAKETYPE(CV_MAT_DEPTH(type), 3);
-        else
-            type = CV_MAKETYPE(CV_MAT_DEPTH(type), 1);
-    }
+    const int type = calcType(m_decoder->type(), m_flags);
 
     // established the required input image size
     Size size = validateInputImageSize(Size(m_width, m_height));
diff --git a/modules/imgcodecs/test/test_png.cpp b/modules/imgcodecs/test/test_png.cpp
@@ -7,19 +7,6 @@ namespace opencv_test { namespace {
 
 #if defined(HAVE_PNG) || defined(HAVE_SPNG)
 
-TEST(Imgcodecs_Png, imread_passing_mat)
-{
-    const string root = cvtest::TS::ptr()->get_data_path();
-    const string imgName = root + "../cv/shared/lena.png";
-
-    Mat ref = imread(imgName);
-    Mat img(ref.size(), ref.type());
-    void* ptr = img.data;
-    imread(imgName, img);
-    EXPECT_EQ(cv::norm(ref, img, NORM_INF), 0);
-    EXPECT_EQ(img.data, ptr);
-}
-
 TEST(Imgcodecs_Png, write_big)
 {
     const string root = cvtest::TS::ptr()->get_data_path();
diff --git a/modules/imgcodecs/test/test_read_write.cpp b/modules/imgcodecs/test/test_read_write.cpp
@@ -282,6 +282,35 @@ TEST(Imgcodecs_Image, regression_9376)
     EXPECT_EQ(32, m.rows);
 }
 
+TEST(Imgcodecs_Image, imread_overload)
+{
+    const string root = cvtest::TS::ptr()->get_data_path();
+    const string imgName = findDataFile("../highgui/readwrite/ordinary.bmp");
+
+    Mat ref = imread(imgName);
+    ASSERT_FALSE(ref.empty());
+    {
+        Mat img(ref.size(), ref.type(), Scalar::all(0)); // existing image
+        void * ptr = img.data;
+        imread(imgName, img);
+        ASSERT_FALSE(img.empty());
+        EXPECT_EQ(cv::norm(ref, img, NORM_INF), 0);
+        EXPECT_EQ(img.data, ptr); // no reallocation
+    }
+    {
+        Mat img; // empty image
+        imread(imgName, img);
+        ASSERT_FALSE(img.empty());
+        EXPECT_EQ(cv::norm(ref, img, NORM_INF), 0);
+    }
+    {
+        UMat img; // empty UMat
+        imread(imgName, img);
+        ASSERT_FALSE(img.empty());
+        EXPECT_EQ(cv::norm(ref, img, NORM_INF), 0);
+    }
+}
+
 //==================================================================================================
 
 TEST(Imgcodecs_Image, write_umat)
