android-bitmap低质量问题

我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

我已经在下面尝试了这些解决方案，但那不起作用

1. 调整ImageView的大小以适应宽高比
2. 将图像拟合到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。

您必须将摄像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！

Answer 2

而不是简单地创建自己的文件夹并在为相机创建意图时给它的uri，例如： Intent intent = new Intent(android.provider.MediaStore.ACTION_IMAGE_CAPTURE); fileUri = GetOutpoutMediaFileUri.getOutputMediaFileUri(MEDIA_TYPE_IMAGE); intent.putExtra(MediaStore.EXTRA_OUTPUT, fileUri); startActivityForResult(intent, 0) Intent intent = new Intent(android.provider.MediaStore.ACTION_IMAGE_CAPTURE); fileUri = GetOutpoutMediaFileUri.getOutputMediaFileUri(MEDIA_TYPE_IMAGE); intent.putExtra(MediaStore.EXTRA_OUTPUT, fileUri); startActivityForResult(intent, 0)