android - 如何在不模糊的情况下或使用 picasso 调整图像大小

Question

我需要帮助改进我的代码。

我在做什么:主要 Activity 中有一个按钮，单击时，用户选择图像，之后，图像通过 Intent 传递给另一个 Activity (add_image.java)和在 ImageView 中显示，然后我将图像发送到服务器。

我的问题:1)我想要将路径图像发送到第二 Intent 然后将其转换为图像的最佳方式
2)然后在不损失很多质量的情况下尽可能多地压缩它。 image现在的大小是 376kb 。所以在我的应用程序中我会显示几张图片，所以在这样的尺寸下它会消耗时间和互联网来加载。(我正在使用 picasso 并且 fit() 没有减小尺寸。)

这是我的代码:

  @Override
       protected void onActivityResult(int requestCode, int resultCode, Intent data) {

           super.onActivityResult(requestCode, resultCode, data);

            if (requestCode == 1 && resultCode == RESULT_OK && data != null && data.getData() != null) {

                //file name
                filePath = data.getData();
                try {
                //  Bundle extras2 = data.getExtras();
                    bitmap  = MediaStore.Images.Media.getBitmap(getContentResolver(), filePath);
                    ByteArrayOutputStream stream = new ByteArrayOutputStream();               
                   byte imageInByte[] = stream.toByteArray();                    
                  Intent i = new Intent(this, AddImage.class);
                  i.putExtra("image", imageInByte);
                  startActivity(i);
                } catch (IOException e) {
                    e.printStackTrace();     }   }   }    

我在这里收到图片

     byte[] byteArray = getIntent().getByteArrayExtra("image");
            encodedImage = Base64.encodeToString(byteArray, Base64);
            bmp = BitmapFactory.decodeByteArray(byteArray, 0, byteArray.length);
          ImageView imageview = (ImageView) findViewById(R.id.imageView);
            imageview.setImageBitmap(bmp);

Answer 1

尝试下面的代码，您可能需要根据您的要求修改一些参数:

创建 MainActivity 如下:

public class MainActivity extends Activity implements OnClickListener {
private final int REQUEST_IMAGE_GALLERY = 2000;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    findViewById(R.id.button).setOnClickListener(this);
}

@Override
public void onClick(View v) {
    switch (v.getId()) {
    case R.id.button:
        pickImageFromGallery();
        break;

    default:
        break;
    }
}

private void pickImageFromGallery() {
    Intent intent = new Intent(Intent.ACTION_PICK,
            android.provider.MediaStore.Images.Media.EXTERNAL_CONTENT_URI);
    intent.setType("image/*");
    startActivityForResult(Intent.createChooser(intent, "Select File"),
            REQUEST_IMAGE_GALLERY);
}

@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
    // TODO Auto-generated method stub
    super.onActivityResult(requestCode, resultCode, data);

    if (resultCode != Activity.RESULT_OK) {
        return;
    }

    if (requestCode == REQUEST_IMAGE_GALLERY) {
        Uri selectedImageUri = data.getData();

        String[] filePathColumn = { MediaStore.Images.Media.DATA };
        Cursor cursor = getContentResolver().query(selectedImageUri,
                filePathColumn, null, null, null);
        cursor.moveToFirst();
        int columnIndex = cursor.getColumnIndex(filePathColumn[0]);
        String picturePath = cursor.getString(columnIndex);
        cursor.close();

        Log.e("PATH", "" + picturePath);
        Intent intent = new Intent(this, AddImage.class);
        intent.putExtra("PATH", picturePath);
        startActivity(intent);

    }
}
}

现在创建 activity_main.xml 如下:

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent" >

<Button
    android:id="@+id/button"
    style="?android:attr/buttonStyleSmall"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:text="ChooseButton" />

    </LinearLayout>

然后我们需要按如下方式创建 AddImage Activity :

public class AddImage extends Activity {
@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.add_image);
    ImageView imageView = (ImageView) findViewById(R.id.image_view);
    if (getIntent() != null) {
        String path = getIntent().getStringExtra("PATH");
        Log.e("PATHR", "" + path);
        new BitmapWorkerTask(imageView).execute(path);
    }

}

private boolean isNeedToBeScaled(String path) {
    File file = new File(path);

    if (file.length() > (1024 * 1024) && isExist(path)) {
        Log.e("SCALEIMAGE", "SACLE");
        return true;
    }
    return false;
}

private boolean isExist(String path) {
    File file = new File(path);
    return file.exists();
}

private Bitmap getScaledImage(String path) {
    BitmapFactory.Options options = new BitmapFactory.Options();
    options.inJustDecodeBounds = true;
    BitmapFactory.decodeFile(path, options);

    int srcWidth = options.outWidth;
    int srcHeight = options.outHeight;
    int[] newWH = new int[2];
    newWH[0] = srcWidth / 2;
    newWH[1] = (newWH[0] * srcHeight) / srcWidth;

    int inSampleSize = 2;
    while (srcWidth / 2 >= newWH[0]) {
        srcWidth /= 2;
        srcHeight /= 2;
        inSampleSize *= 2;

        options.inJustDecodeBounds = false;
        options.inDither = false;
        options.inSampleSize = inSampleSize;
        options.inScaled = false;
        options.inPreferredConfig = Bitmap.Config.RGB_565;
    }
    Bitmap sampledSrcBitmap = BitmapFactory.decodeFile(path, options);

    return sampledSrcBitmap;
}

class BitmapWorkerTask extends AsyncTask<String, Void, Bitmap> {
    private final WeakReference<ImageView> imageViewReference;

    public BitmapWorkerTask(ImageView mImageView) {
        imageViewReference = new WeakReference<ImageView>(mImageView);
    }

    @Override
    protected Bitmap doInBackground(String... params) {
        Bitmap scaled = null;
        if (isNeedToBeScaled(params[0])) {
            Bitmap d;

            d = getScaledImage(params[0]);
            int nh = (int) (d.getHeight() * (512.0 / d.getWidth()));
            scaled = Bitmap.createScaledBitmap(d, 512, nh, true);

        } else {
            scaled = BitmapFactory.decodeFile(params[0], null);
        }
        return scaled;

    }

    @Override
    protected void onPostExecute(Bitmap result) {

        if (imageViewReference != null && result != null) {
            final ImageView imageView = imageViewReference.get();
            if (imageView != null) {
                imageView.setImageBitmap(result);
                imageView.setVisibility(View.VISIBLE);

            }
        }
    }

}
}