表情包斗图，做为人生新晋一大乐事，已是广大网友天天必经的聊天互动环节。什么哄堂大笑、满腹槽点、完全无语……这些万千语言没法贴切描述的情绪细节，总能被一张看似平平无奇的表情包完美形容，可谓一图胜千言，四两拨千斤！android

现在，在表情包斗图进入白热化阶段，人们对表情包的定制化需求日益增多，人人是表情包的搬运工，人人也是潜力热图的创造者！赋予我的制做个性化表情包的能力颇有必要。使用机器学习的图像分割功能，轻松分割复杂图片背景，让表情包制做简单而高效，让咱们来看看如何将一张图片变成传情达意的表情包吧！git

开发准备

Maven仓和SDK的配置步骤能够参考开发者网站中的应用开发介绍github

developer.huawei.com/consumer/cn…算法

配置集成的SDK包

图像分割提供了两种SDK集成方式，一种是预先将分割算法包预先集成在应用中，另外一种是在应用安装运行后，再将所需的算法包下载到应用中，能够根据应用的使用场景和所需效果进行选择。本文是使用了Full SDK的集成方案，在应用的build.gradle文件中，dependencies内添加图像分割的SDK依赖markdown

implementation 'com.huawei.hms:ml-computer-vision-segmentation:2.2.0.300'
implementation 'com.huawei.hms:ml-computer-vision-image-segmentation-body-model:2.2.0.300'
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配置AndroidManifest.xml

打开main文件夹中的AndroidManifest.xml文件，能够根据场景和使用须要，配置读取和写入手机存储的权限，在前添加机器学习

<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
<uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE" />
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在内添加以下语句，当应用安装后，会自动更新最新的机器学习模型到设备异步

<meta-data
    android:name="com.huawei.hms.ml.DEPENDENCY"
    android:value= "imagesuperresolution"/>
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开发步骤

配置存储权限申请

手机的存储权限，除了在Manifest中声明，还须要在Activity中进行动态申请。在MainActivity的onCreate()方法中，调用requestPermission方法，对WRITE_EXTERNAL_STORAGE和READ_EXTERNAL_STORAGE权限进行申请async

protected void onCreate(Bundle savedInstanceState) {
    ……
    requestPermission(Manifest.permission.READ_EXTERNAL_STORAGE);
    requestPermission(Manifest.permission.WRITE_EXTERNAL_STORAGE);
……
}
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requestPermission方法的实现以下，首先对权限进行判断，若是未获取权限，则进行申请，若是已经获取了，则返回ide

private void requestPermission(String permisssions) {
    if (Build.VERSION.SDK_INT < Build.VERSION_CODES.M) {
        return;
    }
		    if (ContextCompat.checkSelfPermission(this, permisssions)
            != PackageManager.PERMISSION_GRANTED) {
        ActivityCompat.requestPermissions(this, new String[]{permisssions}, REQUEST_CODE);
    } else {
        return;
    }
}
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读取相册中的图片

咱们先从相册中选取要进行表情包制做的图片，在xml文件中建立一个按钮chooseImg，点击后调用selectLocalImage方法oop

this.relativeLayoutLoadPhoto = this.findViewById(R.id.chooseImg);

this.relativeLayoutLoadPhoto.setOnClickListener(new View.OnClickListener() {
    @Override
    public void onClick(View v) {
 MainActivity.this.selectLocalImage(StillCutPhotoActivity.this.REQUEST_CHOOSE_ORIGINPIC);
    }
});

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selectLocalImage方法的实现以下

private void selectLocalImage(int requestCode) {
    Intent intent = new Intent(Intent.ACTION_PICK, null);
    intent.setDataAndType(MediaStore.Images.Media.EXTERNAL_CONTENT_URI, "image/*");
    this.startActivityForResult(intent, requestCode);
}
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进行图像分割制做表情包

再建立一个按钮cut，点击后调用createImageTransactor方法，进行图像分割分析器的建立

this.relativeLayoutCut = this.findViewById(R.id.cut);
this.relativeLayoutCut.setOnClickListener(new View.OnClickListener() {
    @Override
    public void onClick(View v) {
        if (MainActivity.this.imageUri == null) {
            Toast.makeText(MainActivity.this.getApplicationContext(), R.string.please_select_picture, Toast.LENGTH_SHORT).show();
        } else {
            MainActivity.this.createImageTransactor();
            Toast.makeText(MainActivity.this.getApplicationContext(), R.string.cut_success, Toast.LENGTH_SHORT).show();
        }
    }
});
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在createImageTransactor方法中，咱们首先建立一个图像分割的分析器，再进行分析器的配置，将其设置为人像分割模式

private MLImageSegmentationAnalyzer analyzer;

MLImageSegmentationSetting setting = new MLImageSegmentationSetting.Factory().setAnalyzerType(MLImageSegmentationSetting.BODY_SEG).create();
this.analyzer = MLAnalyzerFactory.getInstance().getImageSegmentationAnalyzer(setting);
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从相册中选取的文件，经过imageUri，将其打开为Bitmap格式

Pair<Integer, Integer> targetedSize = this.getTargetSize();
int targetWidth = targetedSize.first;
int targetHeight = targetedSize.second;
this.originBitmap = BitmapUtils.loadFromPath(StillCutPhotoActivity.this, this.imageUri, targetWidth, targetHeight);
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以后建立MLFrame，调用asyncAnalyseFrame进行异步图像分割处理

MLFrame mlFrame = new MLFrame.Creator().setBitmap(this.originBitmap).create();
Task<MLImageSegmentation> task = this.analyzer.asyncAnalyseFrame(mlFrame);
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图像分割完成后，对返回的结果进行处理，将去除背景后的图像保存到processedImage中

task.addOnSuccessListener(new OnSuccessListener<MLImageSegmentation>() {
    @Override
    public void onSuccess(MLImageSegmentation mlImageSegmentationResults) {
        // Transacting logic for segment success.
        if (mlImageSegmentationResults != null) {
            StillCutPhotoActivity.this.foreground = mlImageSegmentationResults.getForeground();
            StillCutPhotoActivity.this.preview.setImageBitmap(StillCutPhotoActivity.this.foreground);
            StillCutPhotoActivity.this.processedImage = ((BitmapDrawable) ((ImageView) StillCutPhotoActivity.this.preview).getDrawable()).getBitmap();
        } else {
            StillCutPhotoActivity.this.displayFailure();
        }
    }
}).addOnFailureListener(new OnFailureListener() {
    @Override
    public void onFailure(Exception e) {
        // Transacting logic for segment failure.
        StillCutPhotoActivity.this.displayFailure();
        return;
    }
});
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保存表情包

最后将处理好的图像转换成png格式，存储到系统相册中

public void saveToAlbum(Bitmap bitmap){
    File file = null;
    String fileName = System.currentTimeMillis() +".png";
    File root = new File(Environment.getExternalStorageDirectory().getAbsoluteFile(), this.context.getPackageName());
    File dir = new File(root, "image");
    if(dir.mkdirs() || dir.isDirectory()){
        file = new File(dir, fileName);
    }
    FileOutputStream os = null;
    try {
        os = new FileOutputStream(file);
        bitmap.compress(Bitmap.CompressFormat.PNG, 100, os);
        os.flush();

    } catch (FileNotFoundException e) {
        Log.e(TAG, e.getMessage());
    } catch (IOException e) {
        Log.e(TAG, e.getMessage());
    }finally {
        try {
            if(os != null) {
                os.close();
            }
        }catch (IOException e){
            Log.e(TAG, e.getMessage());
        }
    }
    if(file == null){
        return;
    }
    if(imageUtilCallBack != null) {
        try {
            imageUtilCallBack.callSavePath(file.getCanonicalPath());
        } catch (IOException e) {
            Log.e(TAG, e.getMessage());
        }
    }
    // Gallery refresh.
    if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.KITKAT) {
        String path = null;
        try {
            path = file.getCanonicalPath();
        } catch (IOException e) {
            Log.e(TAG, e.getMessage());
						}
        MediaScannerConnection.scanFile(this.context, new String[]{path}, null,
                new MediaScannerConnection.OnScanCompletedListener() {
                    @Override
                    public void onScanCompleted(String path, Uri uri) {
                        Intent mediaScanIntent = new Intent(Intent.ACTION_MEDIA_SCANNER_SCAN_FILE);
                        mediaScanIntent.setData(uri);
                        ImageUtils.this.context.sendBroadcast(mediaScanIntent);
                    }
                });
    } else {
        String relationDir = file.getParent();
        File file1 = new File(relationDir);
        this.context.sendBroadcast(new Intent(Intent.ACTION_MEDIA_MOUNTED, Uri.fromFile(file1.getAbsoluteFile())));
    }
}
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