OpenALPR是一种使用C ++编写的开源自动车牌识别库，支持多个国家多个地区的车牌。而最近公司想做车牌识别这一块业务，要支持全球多个国家的车牌，于是写了个Demo测试OpenAlpr的接口（有2000次免费机会）。
import android.app.Activity;
import android.content.ContentValues;
import android.content.Intent;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.net.Uri;
import android.os.Build;
import android.os.Bundle;
import android.os.Environment;
import android.provider.MediaStore;
import android.support.v7.app.AppCompatActivity;
import android.text.format.DateFormat;
import android.view.View;
import android.widget.AdapterView;
import android.widget.ArrayAdapter;
import android.widget.Button;
import android.widget.ImageView;
import android.widget.Spinner;
import android.widget.TextView;
import android.widget.Toast;
import com.openalpr.api.DefaultApi;
import com.openalpr.api.invoker.ApiException;
import com.openalpr.api.models.InlineResponse200;
import com.yalantis.ucrop.UCrop;
import com.yalantis.ucrop.UCropActivity;
import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.util.Calendar;
import java.util.Locale;
public class MainActivity extends AppCompatActivity {
private final DefaultApi api = new DefaultApi();
private static final String TAG = "MainActivity";
Button reconize,select;
TextView result,plate;
ImageView showImage;
Spinner spinner;
String secretKey = "sk_960d6f4c62d1c20452c7613e";
String url = "https://qnwww2.autoimg.cn/youchuang/g6/M0A/FA/29/autohomecar__wKgH3FkZCr-AFH7zAAFPFgtP6pc751.jpg?imageView2/2/w/752|watermark/2/text/TEkzMw0K5rG96L2m5LmL5a62/font/5b6u6L2v6ZuF6buR/fontsize/270/fill/d2hpdGU=/dissolve/100/gravity/SouthEast/dx/5/dy/5";
File cameraFile,cropFile;
private boolean isFromfile = false;
String country = "us";
final Integer recognizeVehicle = 0;
final String state = "";
final Integer returnImage = 1;
final Integer topn = 10;
final String prewarp = "";
private String cropPath = "";
String[] countrys ;
String[] countryCodes ;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
reconize = (Button) findViewById(R.id.reconize);
select = (Button) findViewById(R.id.selectImage);
result = (TextView) findViewById(R.id.result);
showImage = (ImageView) findViewById(R.id.imageShow);
plate = (TextView) findViewById(R.id.plate);
spinner = (Spinner) findViewById(R.id.spinner);
// GlideUtils.setUrlImage(this,url,showImage);
countrys = getResources().getStringArray(R.array.countrys);
countryCodes = getResources().getStringArray(R.array.country_codes);
select.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
String filename = DateFormat.format("yyyyMMdd_hhmmss", Calendar.getInstance(Locale.CHINA)) + ".jpg";
cameraFile = new File(Environment.getExternalStorageDirectory() + "/Pictures/Camera/" + filename);
if(!cameraFile.exists()){
try {
cameraFile.createNewFile();
} catch (IOException e) {
e.printStackTrace();
}
}
Intent intent0 = new Intent(MediaStore.ACTION_IMAGE_CAPTURE);
if (Build.VERSION.SDK_INT < 24) {
intent0 = new Intent(MediaStore.ACTION_IMAGE_CAPTURE);
intent0.putExtra("android.intent.extras.CAMERA_FACING", 0);
intent0.putExtra(MediaStore.EXTRA_OUTPUT, Uri.fromFile(cameraFile));
} else {
ContentValues contentValues = new ContentValues(1);
intent0.putExtra("android.intent.extras.CAMERA_FACING", 0);
contentValues.put(MediaStore.Images.Media.DATA, cameraFile.getAbsolutePath());
Uri uri = MainActivity.this.getContentResolver().insert(MediaStore.Images.Media.EXTERNAL_CONTENT_URI, contentValues);
intent0.putExtra(MediaStore.EXTRA_OUTPUT, uri);
}
isFromfile = true;
startActivityForResult(intent0, 200);
}
});
reconize.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
result.setText("正在识别。。。。。");
plate.setText("");
try {
new Thread(){
@Override
public void run() {
super.run();
InlineResponse200 response = null;
try {
if(isFromfile){
response = api.recognizeFile(cropFile, secretKey, country, recognizeVehicle, state, returnImage, topn, prewarp);
}else {
response = api.recognizeUrl(url, secretKey, country, recognizeVehicle, state, returnImage, topn, prewarp);
}
} catch (ApiException e) {
e.printStackTrace();
}
final InlineResponse200 finalResponse = response;
runOnUiThread(new Runnable() {
@Override
public void run() {
if(finalResponse == null){
Toast.makeText(MainActivity.this, "识别失败", Toast.LENGTH_SHORT).show();
return;
}
Toast.makeText(MainActivity.this, "识别成功", Toast.LENGTH_SHORT).show();
if(finalResponse.getResults()!=null && finalResponse.getResults().size()>=1)
plate.setText("车牌号："+finalResponse.getResults().get(0).getPlate());
result.setText("返回结果:"+finalResponse.toString());
}
});
}
}.start();
} catch (Exception e) {
e.printStackTrace();
}
}
});
ArrayAdapter<String> product_adapter = new ArrayAdapter<String>(this, android.R.layout.select_dialog_singlechoice, countrys);
spinner.setAdapter(product_adapter);
spinner.setSelection(12);
spinner.setOnItemSelectedListener(new AdapterView.OnItemSelectedListener() {
@Override
public void onItemSelected(AdapterView<?> parent, View view, int position, long id) {
country = countryCodes[position];
}
@Override
public void onNothingSelected(AdapterView<?> parent) {
}
});
}
@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
super.onActivityResult(requestCode, resultCode, data);
if(resultCode != RESULT_OK){
return;
}
switch (requestCode) {
case 200:
if (!cameraFile.exists()) {
return ;
}
Bitmap bitmap = null;
if (resultCode== Activity.RESULT_OK){
try {
FileInputStream fis = new FileInputStream(cameraFile);
bitmap = BitmapFactory.decodeStream(fis);
fis.close();
} catch (Exception e) {
e.printStackTrace();
}
if (bitmap!=null) {
showImage.setImageBitmap(bitmap);
}
cropPath = startUCrop(this,cameraFile.getPath(),UCrop.REQUEST_CROP,16,9);
}
break;
case UCrop.REQUEST_CROP:
final Uri resultUri = UCrop.getOutput(data);
showImage.setImageURI(resultUri);
cropFile = new File(cropPath);
break;
default:
break;
}
}
/**
* 启动裁剪
* @param activity 上下文
* @param sourceFilePath 需要裁剪图片的绝对路径
* @param requestCode 比如：UCrop.REQUEST_CROP
* @param aspectRatioX 裁剪图片宽高比
* @param aspectRatioY 裁剪图片宽高比
* @return
*/
public static String startUCrop(Activity activity, String sourceFilePath,
int requestCode, float aspectRatioX, float aspectRatioY) {
Uri sourceUri = Uri.fromFile(new File(sourceFilePath));
File outDir = Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_PICTURES);
if (!outDir.exists()) {
outDir.mkdirs();
}
File outFile = new File(outDir, System.currentTimeMillis() + ".jpg");
//裁剪后图片的绝对路径
String cameraScalePath = outFile.getAbsolutePath();
Uri destinationUri = Uri.fromFile(outFile);
//初始化，第一个参数：需要裁剪的图片；第二个参数：裁剪后图片
UCrop uCrop = UCrop.of(sourceUri, destinationUri);
//初始化UCrop配置
UCrop.Options options = new UCrop.Options();
//设置裁剪图片可操作的手势
options.setAllowedGestures(UCropActivity.SCALE, UCropActivity.ROTATE, UCropActivity.ALL);
//是否隐藏底部容器，默认显示
options.setHideBottomControls(true);
// //设置toolbar颜色
// options.setToolbarColor(ActivityCompat.getColor(activity, R.color.colorPrimary));
// //设置状态栏颜色
// options.setStatusBarColor(ActivityCompat.getColor(activity, R.color.colorPrimary));
//是否能调整裁剪框
options.setFreeStyleCropEnabled(true);
//UCrop配置
uCrop.withOptions(options);
//设置裁剪图片的宽高比，比如16：9
uCrop.withAspectRatio(aspectRatioX, aspectRatioY);
//uCrop.useSourceImageAspectRatio();
//跳转裁剪页面
uCrop.start(activity, requestCode);
return cameraScalePath;
}
}
主要分为拍照，裁剪（主要是为了区域更小识别更准确），选取区域，上传图片，获取解析结果。
<item>阿根廷</item>
<item>澳大利亚</item>
<item>巴西</item>
<item>中国</item>
<item>欧洲</item>
<item>英国</item>
<item>印度</item>
<item>印度尼西亚</item>
<item>日本</item>
<item>韩国</item>
<item>中东</item>
<item>新西兰</item>
<item>北美</item>
<item>俄罗斯</item>
<item>沙特阿拉伯</item>
<item>南非</item>
<item>泰国</item>
<item>阿拉伯联合酋长国</item>
对应的code值为
<item>ar</item>
<item>au</item>
<item>br</item>
<item>cn</item>
<item>eu</item>
<item>en</item>
<item>in</item>
<item>id</item>
<item>jp</item>
<item>kr</item>
<item>me</item>
<item>nz</item>
<item>us</item>
<item>ru</item>
<item>sa</item>
<item>za</item>
<item>th</item>
<item>ae</item>
代码地址 GitHub地址