Merge pull request #23597 from dmatveev:dm/gapi_onnx_py_integration

G-API: Integration branch for ONNX & Python-related changes #23597

# Changes overview

## 1. Expose ONNX backend's Normalization and Mean-value parameters in Python

* Since Python G-API bindings rely on `Generic` infer to express Inference, the `Generic` specialization of `onnx::Params` was extended with new methods to control normalization (`/255`) and mean-value; these methods were exposed in the Python bindings
* Found some questionable parts in the existing API which I'd like to review/discuss (see comments)

UPD:
1. Thanks to @TolyaTalamanov normalization inconsistencies have been identified with `squeezenet1.0-9` ONNX model itself; tests using these model were updated to DISABLE normalization and NOT using mean/value.
2. Questionable parts were removed and tests still pass.

### Details (taken from @TolyaTalamanov's comment):

`squeezenet1.0.*onnx` - doesn't require scaling to [0,1] and mean/std because the weights of the first convolution already scaled. ONNX documentation is broken. So the correct approach to use this models is:

1. ONNX: apply preprocessing from the documentation: https://github.com/onnx/models/blob/main/vision/classification/imagenet_preprocess.py#L8-L44 but without normalization step:
```
# DON'T DO IT:
# mean_vec = np.array([0.485, 0.456, 0.406])
# stddev_vec = np.array([0.229, 0.224, 0.225])
# norm_img_data = np.zeros(img_data.shape).astype('float32')
# for i in range(img_data.shape[0]):
#     norm_img_data[i,:,:] = (img_data[i,:,:]/255 - mean_vec[i]) / stddev_vec[i]
#     # add batch channel
#     norm_img_data = norm_img_data.reshape(1, 3, 224, 224).astype('float32')
#     return norm_img_data

# INSTEAD
return img_data.reshape(1, 3, 224, 224)
```

2. G-API: Convert image from BGR to RGB and then pass to `apply` as-is with configuring parameters:
```
net = cv.gapi.onnx.params('squeezenet', model_filename)
net.cfgNormalize('data_0', False)
```
**Note**: Results might be difference because `G-API` doesn't apply central crop but just do resize to model resolution.

---

`squeezenet1.1.*onnx` - requires scaling to [0,1] and mean/std - onnx documentation is correct.
1. ONNX: apply preprocessing from the documentation: https://github.com/onnx/models/blob/main/vision/classification/imagenet_preprocess.py#L8-L44
2. G-API: Convert image from BGR to RGB and then pass to `apply` as-is with configuring parameters:
```
net = cv.gapi.onnx.params('squeezenet', model_filename)
net.cfgNormalize('data_0', True) // default
net.cfgMeanStd('data_0', [0.485, 0.456, 0.406], [0.229, 0.224, 0.225])
```
**Note**: Results might be difference because `G-API` doesn't apply central crop but just do resize to model resolution.

## 2. Expose Fluid & kernel package-related functionality in Python

* `cv::gapi::combine()`
* `cv::GKernelPackage::size()` (mainly for testing purposes)
* `cv::gapi::imgproc::fluid::kernels()`

Added a test for the above.

## 3. Fixed issues with Python stateful kernel handling

Fixed error message when `outMeta()` of custom python operation fails.

## 4. Fixed various issues in Python tests

1. `test_gapi_streaming.py` - fixed behavior of Desync test to avoid sporadic issues
2. `test_gapi_infer_onnx.py` - fixed model lookup (it was still using the ONNX Zoo layout but was NOT using the proper env var we use to point to one).

### Pull Request Readiness Checklist

See details at https://github.com/opencv/opencv/wiki/How_to_contribute#making-a-good-pull-request

- [x] I agree to contribute to the project under Apache 2 License.
- [x] To the best of my knowledge, the proposed patch is not based on a code under GPL or another license that is incompatible with OpenCV
- [x] The PR is proposed to the proper branch
- [x] There is a reference to the original bug report and related work
- [x] There is accuracy test, performance test and test data in opencv_extra repository, if applicable
      Patch to opencv_extra has the same branch name.
- [x] The feature is well documented and sample code can be built with the project CMake

modules/gapi/include/opencv2/gapi/fluid/imgproc.hpp

@@ -13,7 +13,7 @@
 
 namespace cv { namespace gapi { namespace imgproc { namespace fluid {
 
-GAPI_EXPORTS GKernelPackage kernels();
+GAPI_EXPORTS_W GKernelPackage kernels();
 
 }}}}
 

modules/gapi/include/opencv2/gapi/gkernel.hpp

@@ -414,8 +414,8 @@ namespace cv {
     class GAPI_EXPORTS_W_SIMPLE GKernelPackage;
 
 namespace gapi {
-    GAPI_EXPORTS cv::GKernelPackage combine(const cv::GKernelPackage  &lhs,
-                                            const cv::GKernelPackage  &rhs);
+    GAPI_EXPORTS_W cv::GKernelPackage combine(const cv::GKernelPackage  &lhs,
+                                              const cv::GKernelPackage  &rhs);
 
     /// @private
     class GFunctor
@@ -513,7 +513,7 @@ namespace gapi {
          *
          * @return a number of kernels in the package
          */
-        std::size_t size() const;
+        GAPI_WRAP std::size_t size() const;
 
         /**
          * @brief Returns vector of transformations included in the package
@@ -717,6 +717,8 @@ namespace gapi {
     {
         return combine(a, combine(b, rest...));
     }
+    // NB(DM): Variadic-arg version in Python may require the same
+    // approach as used in GComputation::compile/apply.
 
     /** \addtogroup gapi_compile_args
      * @{

modules/gapi/include/opencv2/gapi/infer/bindings_onnx.hpp

@@ -26,6 +26,13 @@ public:
     GAPI_WRAP
     PyParams(const std::string& tag, const std::string& model_path);
 
+    GAPI_WRAP
+    PyParams& cfgMeanStd(const std::string &layer_name,
+                         const cv::Scalar &m,
+                         const cv::Scalar &s);
+    GAPI_WRAP
+    PyParams& cfgNormalize(const std::string &layer_name, bool flag);
+
     GBackend backend() const;
     std::string tag() const;
     cv::util::any params() const;

modules/gapi/include/opencv2/gapi/infer/ie.hpp

@@ -242,7 +242,7 @@ public:
     @param cfg Map of pairs: (config parameter name, config parameter value).
     @return reference to this parameter structure.
     */
-       Params& pluginConfig(const IEConfig& cfg) {
+    Params& pluginConfig(const IEConfig& cfg) {
         desc.config = cfg;
         return *this;
     }

modules/gapi/include/opencv2/gapi/infer/onnx.hpp

@@ -70,6 +70,14 @@ struct ParamDesc {
     std::vector<std::string> names_to_remap; //!< Names of output layers that will be processed in PostProc function.
 
     bool is_generic;
+
+    // TODO: Needs to modify the rest of ParamDesc accordingly to support
+    // both generic and non-generic options without duplication
+    // (as it was done for the OV IE backend)
+    // These values are pushed into the respective vector<> fields above
+    // when the generic infer parameters are unpacked (see GONNXBackendImpl::unpackKernel)
+    std::unordered_map<std::string, std::pair<cv::Scalar, cv::Scalar> > generic_mstd;
+    std::unordered_map<std::string, bool> generic_norm;
 };
 } // namespace detail
 
@@ -298,7 +306,17 @@ public:
     @param model_path path to model file (.onnx file).
     */
     Params(const std::string& tag, const std::string& model_path)
-         : desc{model_path, 0u, 0u, {}, {}, {}, {}, {}, {}, {}, {}, {}, true}, m_tag(tag) {}
+        : desc{model_path, 0u, 0u, {}, {}, {}, {}, {}, {}, {}, {}, {}, true, {}, {} }, m_tag(tag) {}
+
+    void cfgMeanStdDev(const std::string &layer,
+                       const cv::Scalar &m,
+                       const cv::Scalar &s) {
+        desc.generic_mstd[layer] = std::make_pair(m, s);
+    }
+
+    void cfgNormalize(const std::string &layer, bool flag) {
+        desc.generic_norm[layer] = flag;
+    }
 
     // BEGIN(G-API's network parametrization API)
     GBackend      backend() const { return cv::gapi::onnx::backend(); }

modules/gapi/misc/python/pyopencv_gapi.hpp

@@ -785,15 +785,14 @@ static void unpackMetasToTuple(const cv::GMetaArgs&        meta,
     }
 }
 
-static cv::GArg setup_py(cv::detail::PyObjectHolder setup,
-                         const cv::GMetaArgs&       meta,
-                         const cv::GArgs&           gargs)
+static cv::GArg run_py_setup(cv::detail::PyObjectHolder setup,
+                             const cv::GMetaArgs        &meta,
+                             const cv::GArgs            &gargs)
 {
     PyGILState_STATE gstate;
     gstate = PyGILState_Ensure();
 
-    cv::GArg out;
-
+    cv::GArg state;
     try
     {
         // NB: Doesn't increase reference counter (false),
@@ -801,23 +800,20 @@ static cv::GArg setup_py(cv::detail::PyObjectHolder setup,
         // In case exception decrement reference counter.
         cv::detail::PyObjectHolder args(PyTuple_New(meta.size()), false);
         unpackMetasToTuple(meta, gargs, args);
-        // NB: Take an onwership because this state is "Python" type so it will be wrapped as-is
-        // into cv::GArg and stored in GPythonBackend. Object without ownership can't
-        // be dealocated outside this function.
-        cv::detail::PyObjectHolder result(PyObject_CallObject(setup.get(), args.get()), true);
 
+        PyObject *py_kernel_state = PyObject_CallObject(setup.get(), args.get());
         if (PyErr_Occurred())
         {
             PyErr_PrintEx(0);
             PyErr_Clear();
-            throw std::logic_error("Python kernel failed with error!");
+            throw std::logic_error("Python kernel setup failed with error!");
         }
         // NB: In fact it's impossible situation, because errors were handled above.
-        GAPI_Assert(result.get() && "Python kernel returned NULL!");
+        GAPI_Assert(py_kernel_state && "Python kernel setup returned NULL!");
 
-        if (!pyopencv_to(result.get(), out, ArgInfo("arg", false)))
+        if (!pyopencv_to(py_kernel_state, state, ArgInfo("arg", false)))
         {
-            util::throw_error(std::logic_error("Unsupported output meta type"));
+            util::throw_error(std::logic_error("Failed to convert python state"));
         }
     }
     catch (...)
@@ -826,7 +822,7 @@ static cv::GArg setup_py(cv::detail::PyObjectHolder setup,
         throw;
     }
     PyGILState_Release(gstate);
-    return out;
+    return state;
 }
 
 static GMetaArg get_meta_arg(PyObject* obj)
@@ -947,7 +943,7 @@ static PyObject* pyopencv_cv_gapi_kernels(PyObject* , PyObject* py_args, PyObjec
             gapi::python::GPythonFunctor f(
                 id.c_str(), std::bind(run_py_meta, cv::detail::PyObjectHolder{out_meta}, _1, _2),
                 std::bind(run_py_kernel, cv::detail::PyObjectHolder{run}, _1),
-                std::bind(setup_py, cv::detail::PyObjectHolder{setup}, _1, _2));
+                std::bind(run_py_setup, cv::detail::PyObjectHolder{setup}, _1, _2));
             pkg.include(f);
         }
         else

modules/gapi/misc/python/test/test_gapi_infer_onnx.py

@@ -14,21 +14,14 @@ try:
     if sys.version_info[:2] < (3, 0):
         raise unittest.SkipTest('Python 2.x is not supported')
 
-    CLASSIFICATION_MODEL_PATH = "onnx_models/vision/classification/squeezenet/model/squeezenet1.0-9.onnx"
-
-    testdata_required = bool(os.environ.get('OPENCV_DNN_TEST_REQUIRE_TESTDATA', False))
+    CLASSIFICATION_MODEL_PATH = "vision/classification/squeezenet/model/squeezenet1.0-9.onnx"
 
     class test_gapi_infer(NewOpenCVTests):
-        def find_dnn_file(self, filename, required=None):
-            if not required:
-                required = testdata_required
-            return self.find_file(filename, [os.environ.get('OPENCV_DNN_TEST_DATA_PATH', os.getcwd()),
-                                            os.environ['OPENCV_TEST_DATA_PATH']],
-                                required=required)
+        def find_dnn_file(self, filename):
+            return self.find_file(filename, [os.environ.get('OPENCV_GAPI_ONNX_MODEL_PATH')], False)
 
         def test_onnx_classification(self):
             model_path = self.find_dnn_file(CLASSIFICATION_MODEL_PATH)
-
             if model_path is None:
                 raise unittest.SkipTest("Missing DNN test file")
 
@@ -45,6 +38,7 @@ try:
             comp = cv.GComputation(cv.GIn(g_in), cv.GOut(g_out))
 
             net = cv.gapi.onnx.params("squeeze-net", model_path)
+            net.cfgNormalize("data_0", False)
             try:
                 out_gapi = comp.apply(cv.gin(in_mat), cv.gapi.compile_args(cv.gapi.networks(net)))
             except cv.error as err:

modules/gapi/misc/python/test/test_gapi_kernels.py

@@ -0,0 +1,48 @@
+#!/usr/bin/env python
+
+import numpy as np
+import cv2 as cv
+import os
+import sys
+import unittest
+
+from tests_common import NewOpenCVTests
+
+
+try:
+
+    if sys.version_info[:2] < (3, 0):
+        raise unittest.SkipTest('Python 2.x is not supported')
+
+    class gapi_kernels_test(NewOpenCVTests):
+
+        def test_fluid_core_package(self):
+            fluid_core = cv.gapi.core.fluid.kernels()
+            self.assertLess(0, fluid_core.size())
+
+        def test_fluid_imgproc_package(self):
+            fluid_imgproc = cv.gapi.imgproc.fluid.kernels()
+            self.assertLess(0, fluid_imgproc.size())
+
+        def test_combine(self):
+            fluid_core = cv.gapi.core.fluid.kernels()
+            fluid_imgproc = cv.gapi.imgproc.fluid.kernels()
+            fluid = cv.gapi.combine(fluid_core, fluid_imgproc)
+            self.assertEqual(fluid_core.size() + fluid_imgproc.size(), fluid.size())
+
+except unittest.SkipTest as e:
+
+    message = str(e)
+
+    class TestSkip(unittest.TestCase):
+        def setUp(self):
+            self.skipTest('Skip tests: ' + message)
+
+        def test_skip():
+            pass
+
+    pass
+
+
+if __name__ == '__main__':
+    NewOpenCVTests.bootstrap()

modules/gapi/misc/python/test/test_gapi_stateful_kernel.py

@@ -24,7 +24,7 @@ try:
                 in_types=[cv.GOpaque.Int],
                 out_types=[cv.GOpaque.Int])
     class GStatefulCounter:
-        """Accumulate state counter on every call"""
+        """Accumulates state counter on every call"""
 
         @staticmethod
         def outMeta(desc):
@@ -45,6 +45,22 @@ try:
             return state.counter
 
 
+    class SumState:
+        def __init__(self):
+            self.sum = 0
+
+
+    @cv.gapi.op('stateful_sum',
+                in_types=[cv.GOpaque.Int, cv.GOpaque.Int],
+                out_types=[cv.GOpaque.Int])
+    class GStatefulSum:
+        """Accumulates sum on every call"""
+
+        @staticmethod
+        def outMeta(lhs_desc, rhs_desc):
+            return cv.empty_gopaque_desc()
+
+
     class gapi_sample_pipelines(NewOpenCVTests):
         def test_stateful_kernel_single_instance(self):
             g_in  = cv.GOpaque.Int()
@@ -124,6 +140,64 @@ try:
             cc.stop()
 
 
+        def test_stateful_multiple_inputs(self):
+            @cv.gapi.kernel(GStatefulSum)
+            class GStatefulSumImpl:
+                """Implementation for GStatefulCounter operation."""
+
+                @staticmethod
+                def setup(lhs_desc, rhs_desc):
+                    return SumState()
+
+                @staticmethod
+                def run(lhs, rhs, state):
+                    state.sum+= lhs + rhs
+                    return state.sum
+
+
+            g_in1 = cv.GOpaque.Int()
+            g_in2 = cv.GOpaque.Int()
+            g_out = GStatefulSum.on(g_in1, g_in2)
+            comp = cv.GComputation(cv.GIn(g_in1, g_in2), cv.GOut(g_out))
+            pkg  = cv.gapi.kernels(GStatefulSumImpl)
+
+            lhs_list = [1, 10, 15]
+            rhs_list = [2, 14, 32]
+
+            ref_out = 0
+            for lhs, rhs in zip(lhs_list, rhs_list):
+                ref_out += lhs + rhs
+                gapi_out = comp.apply(cv.gin(lhs, rhs), cv.gapi.compile_args(pkg))
+                self.assertEqual(ref_out, gapi_out)
+
+
+        def test_stateful_multiple_inputs_throw(self):
+            @cv.gapi.kernel(GStatefulSum)
+            class GStatefulSumImplIncorrect:
+                """Incorrect implementation for GStatefulCounter operation."""
+
+                # NB: setup methods is intentionally
+                # incorrect - accepts one meta arg instead of two
+                @staticmethod
+                def setup(desc):
+                    return SumState()
+
+                @staticmethod
+                def run(lhs, rhs, state):
+                    state.sum+= lhs + rhs
+                    return state.sum
+
+
+            g_in1 = cv.GOpaque.Int()
+            g_in2 = cv.GOpaque.Int()
+            g_out = GStatefulSum.on(g_in1, g_in2)
+            comp = cv.GComputation(cv.GIn(g_in1, g_in2), cv.GOut(g_out))
+            pkg  = cv.gapi.kernels(GStatefulSumImplIncorrect)
+
+            with self.assertRaises(Exception): comp.apply(cv.gin(42, 42),
+                                                          args=cv.gapi.compile_args(pkg))
+
+
 except unittest.SkipTest as e:
 
     message = str(e)

modules/gapi/misc/python/test/test_gapi_streaming.py

@@ -17,7 +17,7 @@ try:
 
     @cv.gapi.op('custom.delay', in_types=[cv.GMat], out_types=[cv.GMat])
     class GDelay:
-        """Delay for 10 ms."""
+        """Delay for 50 ms."""
 
         @staticmethod
         def outMeta(desc):
@@ -30,7 +30,7 @@ try:
 
         @staticmethod
         def run(img):
-            time.sleep(0.01)
+            time.sleep(0.05)
             return img
 
 
@@ -289,8 +289,7 @@ try:
             ccomp.start()
 
             # Assert
-            max_num_frames  = 10
-            proc_num_frames = 0
+            max_num_frames  = 50
 
             out_counter = 0
             desync_out_counter = 0
@@ -307,12 +306,11 @@ try:
                 else:
                     none_counter += 1
 
-                proc_num_frames += 1
-                if proc_num_frames == max_num_frames:
+                if out_counter == max_num_frames:
                     ccomp.stop()
                     break
 
-            self.assertLess(0, proc_num_frames)
+            self.assertLess(0, out_counter)
             self.assertLess(desync_out_counter, out_counter)
             self.assertLess(0, none_counter)
 

modules/gapi/src/backends/onnx/bindings_onnx.cpp

@@ -8,6 +8,19 @@ cv::gapi::onnx::PyParams::PyParams(const std::string& tag,
                                    const std::string& model_path)
     : m_priv(std::make_shared<Params<cv::gapi::Generic>>(tag, model_path)) {}
 
+cv::gapi::onnx::PyParams& cv::gapi::onnx::PyParams::cfgMeanStd(const std::string &layer_name,
+                                                               const cv::Scalar &m,
+                                                               const cv::Scalar &s) {
+    m_priv->cfgMeanStdDev(layer_name, m, s);
+    return *this;
+}
+
+cv::gapi::onnx::PyParams& cv::gapi::onnx::PyParams::cfgNormalize(const std::string &layer_name,
+                                                                 bool flag) {
+    m_priv->cfgNormalize(layer_name, flag);
+    return *this;
+}
+
 cv::gapi::GBackend cv::gapi::onnx::PyParams::backend() const {
     return m_priv->backend();
 }

modules/gapi/src/backends/onnx/gonnxbackend.cpp

@@ -284,6 +284,7 @@ inline void preprocess(const cv::Mat& src,
         cv::resize(csc, rsz, cv::Size(new_w, new_h));
         if (src.depth() == CV_8U && type == CV_32F) {
             rsz.convertTo(pp, type, ti.normalize ? 1.f / 255 : 1.f);
+
             if (ti.mstd.has_value()) {
                 pp -= ti.mstd->mean;
                 pp /= ti.mstd->stdev;
@@ -1143,24 +1144,31 @@ namespace {
             if (pp.is_generic) {
                 auto& info = cv::util::any_cast<cv::detail::InOutInfo>(op.params);
 
-                for (const auto& a : info.in_names)
-                {
-                    pp.input_names.push_back(a);
-                }
-                // Adding const input is necessary because the definition of input_names
-                // includes const input.
-                for (const auto& a : pp.const_inputs)
+                for (const auto& layer_name : info.in_names)
                 {
-                    pp.input_names.push_back(a.first);
+                    pp.input_names.push_back(layer_name);
+                    if (!pp.generic_mstd.empty()) {
+                        const auto &ms = pp.generic_mstd.at(layer_name);
+                        pp.mean.push_back(ms.first);
+                        pp.stdev.push_back(ms.second);
+                    }
+                    if (!pp.generic_norm.empty()) {
+                        pp.normalize.push_back(pp.generic_norm.at(layer_name));
+                    }
                 }
                 pp.num_in = info.in_names.size();
 
+                // Incorporate extra parameters associated with input layer names
+                // FIXME(DM): The current form assumes ALL input layers require
+                // this information, this is obviously not correct
+
                 for (const auto& a : info.out_names)
                 {
                     pp.output_names.push_back(a);
                 }
                 pp.num_out = info.out_names.size();
-            }
+            } // if(is_generic) -- note, the structure is already filled at the user
+              // end when a non-generic Params are used
 
             gm.metadata(nh).set(ONNXUnit{pp});
             gm.metadata(nh).set(ONNXCallable{ki.run});

modules/gapi/test/infer/gapi_infer_onnx_test.cpp

@@ -423,13 +423,17 @@ public:
         cv::Rect(cv::Point{50, 100}, cv::Size{250, 360})
     };
 
-    void preprocess(const cv::Mat& src, cv::Mat& dst) {
+    // FIXME(dm): There's too much "preprocess" routines in this file
+    // Only one must stay but better design it wisely (and later)
+    void preprocess(const cv::Mat& src, cv::Mat& dst, bool norm = true) {
         const int new_h = 224;
         const int new_w = 224;
         cv::Mat tmp, cvt, rsz;
         cv::resize(src, rsz, cv::Size(new_w, new_h));
-        rsz.convertTo(cvt, CV_32F, 1.f / 255);
-        tmp = (cvt - mean) / std;
+        rsz.convertTo(cvt, CV_32F, norm ? 1.f / 255 : 1.f);
+        tmp = norm
+            ? (cvt - mean) / std
+            : cvt;
         toCHW(tmp, dst);
         dst = dst.reshape(1, {1, 3, new_h, new_w});
     }
@@ -550,16 +554,16 @@ TEST_F(ONNXClassification, Infer)
     in_mat = cv::imread(findDataFile("cv/dpm/cat.png", false));
     // ONNX_API code
     cv::Mat processed_mat;
-    preprocess(in_mat, processed_mat);
+    preprocess(in_mat, processed_mat, false); // NO normalization for 1.0-9, see #23597
     infer<float>(processed_mat, out_onnx);
     // G_API code
     G_API_NET(SqueezNet, <cv::GMat(cv::GMat)>, "squeeznet");
     cv::GMat in;
     cv::GMat out = cv::gapi::infer<SqueezNet>(in);
     cv::GComputation comp(cv::GIn(in), cv::GOut(out));
-    // NOTE: We have to normalize U8 tensor
-    // so cfgMeanStd() is here
-    auto net = cv::gapi::onnx::Params<SqueezNet> { model_path }.cfgMeanStd({ mean }, { std });
+    auto net = cv::gapi::onnx::Params<SqueezNet> {
+        model_path
+    }.cfgNormalize({false});
     comp.apply(cv::gin(in_mat),
                cv::gout(out_gapi.front()),
                cv::compile_args(cv::gapi::networks(net)));
@@ -573,7 +577,7 @@ TEST_F(ONNXClassification, InferTensor)
     in_mat = cv::imread(findDataFile("cv/dpm/cat.png", false));
     // Create tensor
     cv::Mat tensor;
-    preprocess(in_mat, tensor);
+    preprocess(in_mat, tensor, false); // NO normalization for 1.0-9, see #23597
     // ONNX_API code
     infer<float>(tensor, out_onnx);
     // G_API code
@@ -581,7 +585,9 @@ TEST_F(ONNXClassification, InferTensor)
     cv::GMat in;
     cv::GMat out = cv::gapi::infer<SqueezNet>(in);
     cv::GComputation comp(cv::GIn(in), cv::GOut(out));
-    auto net = cv::gapi::onnx::Params<SqueezNet> { model_path };
+    auto net = cv::gapi::onnx::Params<SqueezNet> {
+        model_path
+    }.cfgNormalize({false});
     comp.apply(cv::gin(tensor),
                cv::gout(out_gapi.front()),
                cv::compile_args(cv::gapi::networks(net)));
@@ -596,7 +602,7 @@ TEST_F(ONNXClassification, InferROI)
     const auto ROI = rois.at(0);
     // ONNX_API code
     cv::Mat roi_mat;
-    preprocess(in_mat(ROI), roi_mat);
+    preprocess(in_mat(ROI), roi_mat, false);  // NO normalization for 1.0-9, see #23597
     infer<float>(roi_mat, out_onnx);
     // G_API code
     G_API_NET(SqueezNet, <cv::GMat(cv::GMat)>, "squeeznet");
@@ -604,9 +610,9 @@ TEST_F(ONNXClassification, InferROI)
     cv::GOpaque<cv::Rect> rect;
     cv::GMat out = cv::gapi::infer<SqueezNet>(rect, in);
     cv::GComputation comp(cv::GIn(in, rect), cv::GOut(out));
-    // NOTE: We have to normalize U8 tensor
-    // so cfgMeanStd() is here
-    auto net = cv::gapi::onnx::Params<SqueezNet> { model_path }.cfgMeanStd({ mean }, { std });
+    auto net = cv::gapi::onnx::Params<SqueezNet> {
+        model_path
+    }.cfgNormalize({false});
     comp.apply(cv::gin(in_mat, ROI),
                cv::gout(out_gapi.front()),
                cv::compile_args(cv::gapi::networks(net)));
@@ -621,7 +627,7 @@ TEST_F(ONNXClassification, InferROIList)
     // ONNX_API code
     for (size_t i = 0; i < rois.size(); ++i) {
         cv::Mat roi_mat;
-        preprocess(in_mat(rois[i]), roi_mat);
+        preprocess(in_mat(rois[i]), roi_mat, false);  // NO normalization for 1.0-9, see #23597
         infer<float>(roi_mat, out_onnx);
     }
     // G_API code
@@ -632,7 +638,9 @@ TEST_F(ONNXClassification, InferROIList)
     cv::GComputation comp(cv::GIn(in, rr), cv::GOut(out));
     // NOTE: We have to normalize U8 tensor
     // so cfgMeanStd() is here
-    auto net = cv::gapi::onnx::Params<SqueezNet> { model_path }.cfgMeanStd({ mean }, { std });
+    auto net = cv::gapi::onnx::Params<SqueezNet> {
+        model_path
+    }.cfgNormalize({false});
     comp.apply(cv::gin(in_mat, rois),
                cv::gout(out_gapi),
                cv::compile_args(cv::gapi::networks(net)));
@@ -647,7 +655,7 @@ TEST_F(ONNXClassification, Infer2ROIList)
     // ONNX_API code
     for (size_t i = 0; i < rois.size(); ++i) {
         cv::Mat roi_mat;
-        preprocess(in_mat(rois[i]), roi_mat);
+        preprocess(in_mat(rois[i]), roi_mat, false);   // NO normalization for 1.0-9, see #23597
         infer<float>(roi_mat, out_onnx);
     }
     // G_API code
@@ -658,7 +666,9 @@ TEST_F(ONNXClassification, Infer2ROIList)
     cv::GComputation comp(cv::GIn(in, rr), cv::GOut(out));
     // NOTE: We have to normalize U8 tensor
     // so cfgMeanStd() is here
-    auto net = cv::gapi::onnx::Params<SqueezNet> { model_path }.cfgMeanStd({ mean }, { std });
+    auto net = cv::gapi::onnx::Params<SqueezNet> {
+        model_path
+    }.cfgNormalize({false});
     comp.apply(cv::gin(in_mat, rois),
                cv::gout(out_gapi),
                cv::compile_args(cv::gapi::networks(net)));
@@ -747,7 +757,7 @@ TEST_F(ONNXMediaFrame, InferBGR)
     in_mat = cv::imread(findDataFile("cv/dpm/cat.png", false));
     // ONNX_API code
     cv::Mat processed_mat;
-    preprocess(in_mat, processed_mat);
+    preprocess(in_mat, processed_mat, false); // NO normalization for 1.0-9, see #23597
     infer<float>(processed_mat, out_onnx);
     // G_API code
     auto frame = MediaFrame::Create<TestMediaBGR>(in_mat);
@@ -757,7 +767,9 @@ TEST_F(ONNXMediaFrame, InferBGR)
     cv::GComputation comp(cv::GIn(in), cv::GOut(out));
     // NOTE: We have to normalize U8 tensor
     // so cfgMeanStd() is here
-    auto net = cv::gapi::onnx::Params<SqueezNet> { model_path }.cfgMeanStd({ mean }, { std });
+    auto net = cv::gapi::onnx::Params<SqueezNet> {
+        model_path
+    }.cfgNormalize({false});
     comp.apply(cv::gin(frame),
                cv::gout(out_gapi.front()),
                cv::compile_args(cv::gapi::networks(net)));
@@ -774,7 +786,7 @@ TEST_F(ONNXMediaFrame, InferYUV)
     cv::Mat pp;
     cvtColorTwoPlane(m_in_y, m_in_uv, pp, cv::COLOR_YUV2BGR_NV12);
     cv::Mat processed_mat;
-    preprocess(pp, processed_mat);
+    preprocess(pp, processed_mat, false); // NO normalization for 1.0-9, see #23597
     infer<float>(processed_mat, out_onnx);
     // G_API code
     G_API_NET(SqueezNet, <cv::GMat(cv::GMat)>, "squeeznet");
@@ -783,7 +795,9 @@ TEST_F(ONNXMediaFrame, InferYUV)
     cv::GComputation comp(cv::GIn(in), cv::GOut(out));
     // NOTE: We have to normalize U8 tensor
     // so cfgMeanStd() is here
-    auto net = cv::gapi::onnx::Params<SqueezNet> { model_path }.cfgMeanStd({ mean }, { std });
+    auto net = cv::gapi::onnx::Params<SqueezNet> {
+        model_path
+    }.cfgNormalize({false});
     comp.apply(cv::gin(frame),
                cv::gout(out_gapi.front()),
                cv::compile_args(cv::gapi::networks(net)));
@@ -798,7 +812,7 @@ TEST_F(ONNXMediaFrame, InferROIBGR)
     auto frame = MediaFrame::Create<TestMediaBGR>(in_mat);
     // ONNX_API code
     cv::Mat roi_mat;
-    preprocess(in_mat(rois.front()), roi_mat);
+    preprocess(in_mat(rois.front()), roi_mat, false);  // NO normalization for 1.0-9, see #23597
     infer<float>(roi_mat, out_onnx);
     // G_API code
     G_API_NET(SqueezNet, <cv::GMat(cv::GMat)>, "squeeznet");
@@ -808,7 +822,9 @@ TEST_F(ONNXMediaFrame, InferROIBGR)
     cv::GComputation comp(cv::GIn(in, rect), cv::GOut(out));
     // NOTE: We have to normalize U8 tensor
     // so cfgMeanStd() is here
-    auto net = cv::gapi::onnx::Params<SqueezNet> { model_path }.cfgMeanStd({ mean }, { std });
+    auto net = cv::gapi::onnx::Params<SqueezNet> {
+        model_path
+    }.cfgNormalize({false});
     comp.apply(cv::gin(frame, rois.front()),
                cv::gout(out_gapi.front()),
                cv::compile_args(cv::gapi::networks(net)));
@@ -825,7 +841,7 @@ TEST_F(ONNXMediaFrame, InferROIYUV)
     cv::Mat pp;
     cvtColorTwoPlane(m_in_y, m_in_uv, pp, cv::COLOR_YUV2BGR_NV12);
     cv::Mat roi_mat;
-    preprocess(pp(rois.front()), roi_mat);
+    preprocess(pp(rois.front()), roi_mat, false);  // NO normalization for 1.0-9, see #23597
     infer<float>(roi_mat, out_onnx);
     // G_API code
     G_API_NET(SqueezNet, <cv::GMat(cv::GMat)>, "squeeznet");
@@ -835,7 +851,9 @@ TEST_F(ONNXMediaFrame, InferROIYUV)
     cv::GComputation comp(cv::GIn(in, rect), cv::GOut(out));
     // NOTE: We have to normalize U8 tensor
     // so cfgMeanStd() is here
-    auto net = cv::gapi::onnx::Params<SqueezNet> { model_path }.cfgMeanStd({ mean }, { std });
+    auto net = cv::gapi::onnx::Params<SqueezNet> {
+        model_path
+    }.cfgNormalize({false});
     comp.apply(cv::gin(frame, rois.front()),
                cv::gout(out_gapi.front()),
                cv::compile_args(cv::gapi::networks(net)));
@@ -851,7 +869,7 @@ TEST_F(ONNXMediaFrame, InferListBGR)
     // ONNX_API code
     for (size_t i = 0; i < rois.size(); ++i) {
         cv::Mat roi_mat;
-        preprocess(in_mat(rois[i]), roi_mat);
+        preprocess(in_mat(rois[i]), roi_mat, false);  // NO normalization for 1.0-9, see #23597
         infer<float>(roi_mat, out_onnx);
     }
     // G_API code
@@ -862,7 +880,9 @@ TEST_F(ONNXMediaFrame, InferListBGR)
     cv::GComputation comp(cv::GIn(in, rr), cv::GOut(out));
     // NOTE: We have to normalize U8 tensor
     // so cfgMeanStd() is here
-    auto net = cv::gapi::onnx::Params<SqueezNet> { model_path }.cfgMeanStd({ mean }, { std });
+    auto net = cv::gapi::onnx::Params<SqueezNet> {
+        model_path
+    }.cfgNormalize({false});
     comp.apply(cv::gin(frame, rois),
                cv::gout(out_gapi),
                cv::compile_args(cv::gapi::networks(net)));
@@ -880,7 +900,7 @@ TEST_F(ONNXMediaFrame, InferListYUV)
     cvtColorTwoPlane(m_in_y, m_in_uv, pp, cv::COLOR_YUV2BGR_NV12);
     for (size_t i = 0; i < rois.size(); ++i) {
         cv::Mat roi_mat;
-        preprocess(pp(rois[i]), roi_mat);
+        preprocess(pp(rois[i]), roi_mat, false);   // NO normalization for 1.0-9, see #23597
         infer<float>(roi_mat, out_onnx);
     }
     // G_API code
@@ -891,7 +911,9 @@ TEST_F(ONNXMediaFrame, InferListYUV)
     cv::GComputation comp(cv::GIn(in, rr), cv::GOut(out));
     // NOTE: We have to normalize U8 tensor
     // so cfgMeanStd() is here
-    auto net = cv::gapi::onnx::Params<SqueezNet> { model_path }.cfgMeanStd({ mean }, { std });
+    auto net = cv::gapi::onnx::Params<SqueezNet> {
+        model_path
+    }.cfgNormalize({false});
     comp.apply(cv::gin(frame, rois),
                cv::gout(out_gapi),
                cv::compile_args(cv::gapi::networks(net)));
@@ -933,7 +955,7 @@ TEST_F(ONNXMediaFrame, InferList2BGR)
     // ONNX_API code
     for (size_t i = 0; i < rois.size(); ++i) {
         cv::Mat roi_mat;
-        preprocess(in_mat(rois[i]), roi_mat);
+        preprocess(in_mat(rois[i]), roi_mat, false);  // NO normalization for 1.0-9, see #23597
         infer<float>(roi_mat, out_onnx);
     }
     // G_API code
@@ -944,7 +966,9 @@ TEST_F(ONNXMediaFrame, InferList2BGR)
     cv::GComputation comp(cv::GIn(in, rr), cv::GOut(out));
     // NOTE: We have to normalize U8 tensor
     // so cfgMeanStd() is here
-    auto net = cv::gapi::onnx::Params<SqueezNet> { model_path }.cfgMeanStd({ mean }, { std });
+    auto net = cv::gapi::onnx::Params<SqueezNet> {
+        model_path
+    }.cfgNormalize({false});
     comp.apply(cv::gin(frame, rois),
                cv::gout(out_gapi),
                cv::compile_args(cv::gapi::networks(net)));