android-bitmap低质量问题

Question

我刚刚创建了一些函数来从相机拍摄照片并将结果图像放入imageview.而我发现我的拍摄质量非常糟糕.

以下是一些代码:

 @Override
    protected void onActivityResult(int requestCode, int resultCode, Intent data) {
        if (requestCode == CAMERA_REQUEST && resultCode == RESULT_OK) {
            Bitmap photo = (Bitmap) data.getExtras().get("data");
            picture.setImageBitmap(photo);
        }
    }

View.OnClickListener camerabtnlistener = new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            Intent cameraIntent = new Intent(MediaStore.ACTION_IMAGE_CAPTURE);
            startActivityForResult(cameraIntent, CAMERA_REQUEST);
        }
    };


@Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_admin_help_3);
        btnPicture = (Button) findViewById(R.id.btnPicture);
        picture= (ImageView) findViewById(R.id.picture);
        mToolbar = (Toolbar) findViewById(R.id.toolbar);
        layoutPic = (RelativeLayout) findViewById(R.id.layoutPic);
        setSupportActionBar(mToolbar);

        getSupportActionBar().setDisplayOptions(ActionBar.DISPLAY_SHOW_HOME, ActionBar.DISPLAY_SHOW_CUSTOM);
        getSupportActionBar().setDisplayHomeAsUpEnabled(true);
        getSupportActionBar().setHomeButtonEnabled(true);

        btnPicture.setOnClickListener(camerabtnlistener);

    }

和xml

<ImageView
            android:id="@+id/picture"
            android:layout_width="fill_parent"
            android:layout_height="wrap_content"
            android:src="@drawable/test_admin_big"
            android:adjustViewBounds="true"/>

我已经在下面尝试过这些解决方案,但那不起作用

1. 调整ImageView的大小以适应宽高比
2. 将图像调整到ImageView中,保持纵横比,然后将ImageView调整为图像尺寸？
3. Android位图质量问题

请指教

谢谢

Answer 1

如果你使用Bundle extras = data.getExtras(); 在你的onActivityResult然后它将返回缩略图而不是实际图像.

这是我用于捕获和保存摄像机图像然后将其显示到imageview的代码.

您必须将相机图像保存到特定位置,然后从该位置获取.

这是用于打开捕获相机图像活动的方法.

private static final int CAMERA_PHOTO = 111;
private Uri imageToUploadUri;

private void captureCameraImage() {
        Intent chooserIntent = new Intent(MediaStore.ACTION_IMAGE_CAPTURE);
        File f = new File(Environment.getExternalStorageDirectory(), "POST_IMAGE.jpg");
        chooserIntent.putExtra(MediaStore.EXTRA_OUTPUT, Uri.fromFile(f));
        imageToUploadUri = Uri.fromFile(f);
        startActivityForResult(chooserIntent, CAMERA_PHOTO);
    }

那么你的onActivityResult()方法应该是这样的.

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

            if (requestCode == CAMERA_PHOTO && resultCode == Activity.RESULT_OK) {
                if(imageToUploadUri != null){
                    Uri selectedImage = imageToUploadUri;
                    getContentResolver().notifyChange(selectedImage, null);
                    Bitmap reducedSizeBitmap = getBitmap(imageToUploadUri.getPath());
                    if(reducedSizeBitmap != null){
                        imageview.setImageBitmap(reducedSizeBitmap);
                    }else{
                        Toast.makeText(this,"Error while capturing Image",Toast.LENGTH_LONG).show();
                    }
                }else{
                    Toast.makeText(this,"Error while capturing Image",Toast.LENGTH_LONG).show();
                }
            } 
        }

这是onActivityResult()中使用的getBitmap()方法.

private Bitmap getBitmap(String path) {

        Uri uri = Uri.fromFile(new File(path));
        InputStream in = null;
        try {
            final int IMAGE_MAX_SIZE = 1200000; // 1.2MP
            in = getContentResolver().openInputStream(uri);

            // Decode image size
            BitmapFactory.Options o = new BitmapFactory.Options();
            o.inJustDecodeBounds = true;
            BitmapFactory.decodeStream(in, null, o);
            in.close();


            int scale = 1;
            while ((o.outWidth * o.outHeight) * (1 / Math.pow(scale, 2)) >
                    IMAGE_MAX_SIZE) {
                scale++;
            }
            Log.d("", "scale = " + scale + ", orig-width: " + o.outWidth + ", orig-height: " + o.outHeight);

            Bitmap b = null;
            in = getContentResolver().openInputStream(uri);
            if (scale > 1) {
                scale--;
                // scale to max possible inSampleSize that still yields an image
                // larger than target
                o = new BitmapFactory.Options();
                o.inSampleSize = scale;
                b = BitmapFactory.decodeStream(in, null, o);

                // resize to desired dimensions
                int height = b.getHeight();
                int width = b.getWidth();
                Log.d("", "1th scale operation dimenions - width: " + width + ", height: " + height);

                double y = Math.sqrt(IMAGE_MAX_SIZE
                        / (((double) width) / height));
                double x = (y / height) * width;

                Bitmap scaledBitmap = Bitmap.createScaledBitmap(b, (int) x,
                        (int) y, true);
                b.recycle();
                b = scaledBitmap;

                System.gc();
            } else {
                b = BitmapFactory.decodeStream(in);
            }
            in.close();

            Log.d("", "bitmap size - width: " + b.getWidth() + ", height: " +
                    b.getHeight());
            return b;
        } catch (IOException e) {
            Log.e("", e.getMessage(), e);
            return null;
        }
    }

我希望它有所帮助!