Merge pull request #24426 from dkurt:qrcode_eci_encoding

Consider QRCode ECI encoding #24426

### Pull Request Readiness Checklist

related: https://github.com/opencv/opencv/pull/24350#pullrequestreview-1661658421

1. Add `getEncoding` method to obtain ECI number
2. Add `detectAndDecodeBytes`, `decodeBytes`, `decodeBytesMulti`, `detectAndDecodeBytesMulti` methods in Python (return `bytes`) and Java (return `byte[]`)
3. Allow Python bytes to std::string conversion in general and add `encode(byte[] encoded_info, Mat qrcode)` in Java


    Python example with Kanji encoding:
    ```python
    img = cv.imread("test.png")
    detect = cv.QRCodeDetector()
    data, points, straight_qrcode = detect.detectAndDecodeBytes(img)
    print(data)
    print(detect.getEncoding(), cv.QRCodeEncoder_ECI_SHIFT_JIS)
    print(data.decode("shift-jis"))
    ```
    ```
    b'\x82\xb1\x82\xf1\x82\xc9\x82\xbf\x82\xcd\x90\xa2\x8aE'
    20 20
    こんにちは世界
    ```

    source: https://github.com/opencv/opencv/blob/ba4d6c859d21536f84e0328c16f4cc3e96bf3065/modules/objdetect/test/test_qrcode_encode.cpp#L332

    ![test](https://github.com/opencv/opencv/assets/25801568/0b5eefa8-918a-4c42-9acb-830f23c0ea9f)


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/objdetect/include/opencv2/objdetect.hpp

@@ -729,7 +729,8 @@ public:
     };
 
     enum ECIEncodings {
-        ECI_UTF8 = 26
+        ECI_SHIFT_JIS = 20,
+        ECI_UTF8 = 26,
     };
 
     /** @brief QR code encoder parameters. */
@@ -808,6 +809,13 @@ public:
      */
     CV_WRAP std::string detectAndDecodeCurved(InputArray img, OutputArray points=noArray(),
                                               OutputArray straight_qrcode = noArray());
+
+    /** @brief Returns a kind of encoding for the decoded info from the latest @ref decode or @ref detectAndDecode call
+    @param codeIdx an index of the previously decoded QR code.
+                   When @ref decode or @ref detectAndDecode is used, valid value is zero.
+                   For @ref decodeMulti or @ref detectAndDecodeMulti use indices corresponding to the output order.
+    */
+    CV_WRAP QRCodeEncoder::ECIEncodings getEncoding(int codeIdx = 0);
 };
 
 class CV_EXPORTS_W_SIMPLE QRCodeDetectorAruco : public GraphicalCodeDetector {

modules/objdetect/include/opencv2/objdetect/graphical_code_detector.hpp

@@ -73,6 +73,17 @@ public:
     */
     CV_WRAP bool detectAndDecodeMulti(InputArray img, CV_OUT std::vector<std::string>& decoded_info, OutputArray points = noArray(),
                                       OutputArrayOfArrays straight_code = noArray()) const;
+
+#ifdef OPENCV_BINDINGS_PARSER
+    CV_WRAP_AS(detectAndDecodeBytes) NativeByteArray detectAndDecode(InputArray img, OutputArray points = noArray(),
+                                                                     OutputArray straight_code = noArray()) const;
+    CV_WRAP_AS(decodeBytes) NativeByteArray decode(InputArray img, InputArray points, OutputArray straight_code = noArray()) const;
+    CV_WRAP_AS(decodeBytesMulti) bool decodeMulti(InputArray img, InputArray points, CV_OUT std::vector<NativeByteArray>& decoded_info,
+                                                  OutputArrayOfArrays straight_code = noArray()) const;
+    CV_WRAP_AS(detectAndDecodeBytesMulti) bool detectAndDecodeMulti(InputArray img, CV_OUT std::vector<NativeByteArray>& decoded_info, OutputArray points = noArray(),
+                                                                    OutputArrayOfArrays straight_code = noArray()) const;
+#endif
+
     struct Impl;
 protected:
     Ptr<Impl> p;