Merge pull request #27600 from atamas19:ov_output_clamping

G-API: Implement cfgClampOutputs option to OpenVINO Params #27600

Added the option `cfgClampOutputs` to control where output clamping is performed for OpenVINO models. When enabled, output values are clamped in the PrePostProcessor stage instead of by the device or plugin. This provides a consistent and standardized clamping method across devices, helping to maintain accuracy regardless of device-specific clamping behavior.

### Pull Request Readiness Checklist

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- [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
- [ ] There is a reference to the original bug report and related work
- [ ] 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/infer/ov.hpp

@@ -66,6 +66,8 @@ struct ParamDesc {
         LayerVariantAttr<std::vector<float>> scale_values;
 
         LayerVariantAttr<int> interpolation;
+
+        bool clamp_outputs = false;
     };
 
     struct CompiledModel {
@@ -356,6 +358,24 @@ public:
         return *this;
     }
 
+    /** @brief Enables or disables clamping of model outputs in the PrePostProcessor.
+
+    By default, output values are clamped to the valid range for the output precision
+    by the device or plugin. Enabling this option moves clamping to the PrePostProcessor stage.
+
+    @note This feature is only available with OpenVINO 2025.2 and newer.
+
+    @param flag If true, clamping is performed in the PrePostProcessor;
+    otherwise, it is handled by the device or plugin.
+    @return reference to this parameter structure.
+    */
+    Params<Net>&
+    cfgClampOutputs(bool flag = true) {
+        detail::getModelToSetAttrOrThrow(m_desc.kind, "clamp outputs")
+            .clamp_outputs = std::move(flag);
+        return *this;
+    }
+
     /** @brief Specifies the new shape for input layers.
 
     The function is used to set new shape for input layers.
@@ -625,6 +645,14 @@ public:
         return *this;
     }
 
+    /** @see ov::Params::cfgClampOutputs. */
+    Params&
+    cfgClampOutputs(bool flag = true) {
+        detail::getModelToSetAttrOrThrow(m_desc.kind, "clamp outputs")
+            .clamp_outputs = std::move(flag);
+        return *this;
+    }
+
     /** @see ov::Params::cfgReshape. */
     Params& cfgReshape(std::vector<size_t> new_shape) {
         detail::getModelToSetAttrOrThrow(m_desc.kind, "reshape")