From d6cea3c43ef85cab22af0ef59bf3325ca4f2b87e Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Artur=20Ban=CC=81kowski?= <abankowski@tandk.pl>
Date: Mon, 26 Sep 2016 23:18:59 +0200
Subject: [PATCH] Enhance interop with Java

When working with JVM based language and OpenCV you may have a ptr to
the native Mat data. This binding allows passing it to the OpenALPR.

Usage:
Mat mat = ...
alpr.recognize(mat.dataAddr(), mat.channels(), mat.width(), mat.height())
---
 src/bindings/java/com_openalpr_jni_Alpr.h      |  8 ++++++++
 src/bindings/java/openalprjni.cpp              | 18 ++++++++++++++++++
 .../java/src/com/openalpr/jni/Alpr.java        | 13 +++++++++++++
 3 files changed, 39 insertions(+)

diff --git a/src/bindings/java/com_openalpr_jni_Alpr.h b/src/bindings/java/com_openalpr_jni_Alpr.h
index 95e3983..5418502 100644
--- a/src/bindings/java/com_openalpr_jni_Alpr.h
+++ b/src/bindings/java/com_openalpr_jni_Alpr.h
@@ -47,6 +47,14 @@ JNIEXPORT jstring JNICALL Java_com_openalpr_jni_Alpr_native_1recognize__Ljava_la
 JNIEXPORT jstring JNICALL Java_com_openalpr_jni_Alpr_native_1recognize___3B
   (JNIEnv *, jobject, jbyteArray);
 
+/*
+ * Class:     com_openalpr_jni_Alpr
+ * Method:    native_recognize
+ * Signature: (JIII)Ljava/lang/String;
+ */
+JNIEXPORT jstring JNICALL Java_com_openalpr_jni_Alpr_native_1recognize__JIII
+  (JNIEnv *, jobject, jlong, jint, jint, jint);
+
 /*
  * Class:     com_openalpr_jni_Alpr
  * Method:    set_default_region
diff --git a/src/bindings/java/openalprjni.cpp b/src/bindings/java/openalprjni.cpp
index 7863843..711b17b 100644
--- a/src/bindings/java/openalprjni.cpp
+++ b/src/bindings/java/openalprjni.cpp
@@ -88,6 +88,24 @@ JNIEXPORT jstring JNICALL Java_com_openalpr_jni_Alpr_native_1recognize___3B
     return env->NewStringUTF(json.c_str());
   }
 
+JNIEXPORT jstring JNICALL Java_com_openalpr_jni_Alpr_native_1recognize__JIII
+  (JNIEnv *env, jobject thisObj, jlong data, jint bytesPerPixel, jint width, jint height)
+  {
+    //printf("Recognize data pointer");
+
+    AlprResults results = nativeAlpr->recognize(
+            reinterpret_cast<unsigned char*>(data),
+            static_cast<int>(bytesPerPixel),
+            static_cast<int>(width),
+            static_cast<int>(height),
+            std::vector<AlprRegionOfInterest>());
+
+    std::string json = Alpr::toJson(results);
+
+    return env->NewStringUTF(json.c_str());
+  }
+
+
 JNIEXPORT void JNICALL Java_com_openalpr_jni_Alpr_set_1default_1region
   (JNIEnv *env, jobject thisObj, jstring jdefault_region)
   {
diff --git a/src/bindings/java/src/com/openalpr/jni/Alpr.java b/src/bindings/java/src/com/openalpr/jni/Alpr.java
index ce49488..e72816b 100644
--- a/src/bindings/java/src/com/openalpr/jni/Alpr.java
+++ b/src/bindings/java/src/com/openalpr/jni/Alpr.java
@@ -15,6 +15,7 @@ public class Alpr {
     private native boolean is_loaded();
     private native String native_recognize(String imageFile);
     private native String native_recognize(byte[] imageBytes);
+    private native String native_recognize(long imageData, int bytesPerPixel, int imgWidth, int imgHeight);
 
     private native void set_default_region(String region);
     private native void detect_region(boolean detectRegion);
@@ -62,6 +63,18 @@ public class Alpr {
     }
 
 
+    public AlprResults recognize(long imageData, int bytesPerPixel, int imgWidth, int imgHeight) throws AlprException
+    {
+        try {
+            String json = native_recognize(imageData, bytesPerPixel, imgWidth, imgHeight);
+            return new AlprResults(json);
+        } catch (JSONException e)
+        {
+            throw new AlprException("Unable to parse ALPR results");
+        }
+    }
+
+
     public void setTopN(int topN)
     {
         set_top_n(topN);