使用ACTION_IMAGE_CAPTURE时，为什么预览图片模糊 [英] When using ACTION_IMAGE_CAPTURE why is the preview image blurry

问题描述

我已经设法实现ACTION_IMAGE_CAPTURE目的的使用，以便在我的应用程序中拍摄照片。由于某些原因，当拍摄照片时，预览图像（在它被发送回我的应用程序之前显示有刻度/十字图标的图像）是正方形和真正低分辨率，即使我已经设法保存到存储不是。我已经通过所有的问题，抱怨一个低质量的图像被返回，所有的答案给出了如何获得更高质量的图像在您的应用程序本身的解决方案，而不是如何告诉相机应用程序使用完整的质量预览。任何帮助将非常感激。

I have managed to implement usage of the ACTION_IMAGE_CAPTURE intend in order to take a photo in my app. For some reason, when the photo is taken, the preview image (the image that is displayed with the tick/cross icon before it is sent back to my app) is square and really low resolution, even though the picture which I have managed to save to storage is not. I have been through all the questions that complain about a low quality image being returned, and all the answers give solutions on how to get the higher quality image in your app itself, not how to tell the camera app to use a full quality preview. Any help will be greatfully appreciated!

推荐答案

尝试检查下面的代码工作完美的应用程序。

try to check below code work for my app perfect.

TakeImageActivity.java

import java.io.File;
import java.text.SimpleDateFormat;
import java.util.ArrayList;
import java.util.Date;
import java.util.Locale;

import android.content.Intent;
import android.content.pm.PackageManager;
import android.database.Cursor;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.net.Uri;
import android.os.Bundle;
import android.os.Environment;
import android.provider.MediaStore;
import android.util.Log;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.ImageView;
import android.widget.Toast;

public class TakeImageActivity extends ActivityBase implements OnClickListener {

    File file,mFileTemp;

    Button buttonTakeImageCam;
    ImageView imageView;
    Uri mPhotoUri;
    Bitmap thumbnail;
    private Uri fileUri;
    private static final String IMAGE_DIRECTORY_NAME = "PhotoEditor Camera";
    public static final int MEDIA_TYPE_IMAGE = 1;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        // TODO Auto-generated method stub
        super.onCreate(savedInstanceState);
        setContentView(R.layout.take_image_activity);

        file = new File(Environment.getExternalStorageDirectory()
                .getAbsolutePath() + "/FrameImages");

        initializetion();

    }

    private void initializetion() {
        // TODO Auto-generated method stub
        buttonTakeImageCam = (Button) findViewById(R.id.buttonTakeImageCam);
        buttonTakeImageCam.setOnClickListener(this);

        if (!isDeviceSupportCamera()) {
            Toast.makeText(getApplicationContext(),
                    "Sorry! Your device doesn't support camera",
                    Toast.LENGTH_LONG).show();
            // will close the app if the device does't have camera
            finish();
        }
    }

    private boolean isDeviceSupportCamera() {
        if (getApplicationContext().getPackageManager().hasSystemFeature(
                PackageManager.FEATURE_CAMERA)) {
            // this device has a camera
            return true;
        } else {
            // no camera on this device
            return false;
        }
    }

    public Uri getOutputMediaFileUri(int type) {
        return Uri.fromFile(getOutputMediaFile(type));
    }

    private static File getOutputMediaFile(int type) {

        // External sdcard location
        File mediaStorageDir = new File(
                Environment
                        .getExternalStoragePublicDirectory(Environment.DIRECTORY_PICTURES),
                IMAGE_DIRECTORY_NAME);

        // Create the storage directory if it does not exist
        if (!mediaStorageDir.exists()) {
            if (!mediaStorageDir.mkdirs()) {
                Log.d(IMAGE_DIRECTORY_NAME, "Oops! Failed create "
                        + IMAGE_DIRECTORY_NAME + " directory");
                return null;
            }
        }
        String timeStamp = new SimpleDateFormat("yyyyMMdd_HHmmss",
                Locale.getDefault()).format(new Date());
        File mediaFile;
        if (type == MEDIA_TYPE_IMAGE) {
            mediaFile = new File(mediaStorageDir.getPath() + File.separator
                    + "IMG_" + timeStamp + ".jpg");
        } else {
            return null;
        }

        return mediaFile;
    }


    @Override
    public void onClick(View v) {
        // TODO Auto-generated method stub

        switch (v.getId()) {

        case R.id.buttonTakeImageCam:
            Intent intent = new Intent(MediaStore.ACTION_IMAGE_CAPTURE);

            fileUri = getOutputMediaFileUri(MEDIA_TYPE_IMAGE);

            intent.putExtra(MediaStore.EXTRA_OUTPUT, fileUri);

            // start the image capture Intent
            startActivityForResult(intent, 2);
            break;
        default:
            break;
        }

    }

    @Override
    protected void onActivityResult(int requestCode, int resultCode, Intent data) {
        // TODO Auto-generated method stub
        if (resultCode != RESULT_OK)
            return;

        switch (requestCode) {

        case 2:
                if (resultCode == RESULT_OK) {
                    // successfully captured the image
                    // display it in image view
                    previewCapturedImage();
                } else if (resultCode == RESULT_CANCELED) {
                    // user cancelled Image capture
                    Toast.makeText(getApplicationContext(),
                            "User cancelled image capture", Toast.LENGTH_SHORT)
                            .show();
                } else {
                    // failed to capture image
                    Toast.makeText(getApplicationContext(),
                            "Sorry! Failed to capture image", Toast.LENGTH_SHORT)
                            .show();
                }
            break;
        }
    }
        private void previewCapturedImage() {
            try {
                // bimatp factory
                BitmapFactory.Options options = new BitmapFactory.Options();

                // downsizing image as it throws OutOfMemory Exception for larger
                // images
                options.inSampleSize = 2;

                final Bitmap bitmap = BitmapFactory.decodeFile(fileUri.getPath(),
                        options);

                  //Set image here
                imgPreview.setImageBitmap(bitmap);

            } catch (NullPointerException e) {
                e.printStackTrace();
            }
        }

    public Bitmap getPreview(String fileName) {
        File image = new File(fileName);

        BitmapFactory.Options bounds = new BitmapFactory.Options();
        bounds.inJustDecodeBounds = true;
        BitmapFactory.decodeFile(image.getPath(), bounds);
        if ((bounds.outWidth == -1) || (bounds.outHeight == -1)) {
            return null;
        }
        int originalSize = (bounds.outHeight > bounds.outWidth) ? bounds.outHeight
                : bounds.outWidth;
        BitmapFactory.Options opts = new BitmapFactory.Options();
        opts.inSampleSize = originalSize / 64;
        // opts.inSampleSize = originalSize;
        return BitmapFactory.decodeFile(image.getPath());
    }

    public String getPath(Uri uri) {
        String[] projection = { MediaStore.Images.Media.DATA };
        Cursor cursor = managedQuery(uri, projection, null, null, null);
        int column_index = cursor
                .getColumnIndexOrThrow(MediaStore.Images.Media.DATA);
        cursor.moveToFirst();
        return cursor.getString(column_index);
    }
}

take_image_activity.xml / p>

take_image_activity.xml

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    android:layout_gravity="center" >

    <Button 
        android:id="@+id/buttonTakeImageCam"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_centerVertical="true"
        android:layout_centerHorizontal="true"
        android:layout_marginTop="10dp"
        android:textSize="25sp"
        android:text="Camera"/>

</RelativeLayout>

AndroidManifest.xml

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.camera.photo"
    android:versionCode="1"
    android:versionName="1.0" >

    <uses-sdk
        android:minSdkVersion="9" />

    <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
    <uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE" />
    <uses-permission android:name="android.permission.CAMERA"/>
    <uses-feature android:name="android.hardware.camera" android:required="true"/>

    <application
        android:icon="@drawable/ic_launcher"
        android:largeHeap="true"
        android:label="@string/app_name" >
        <activity
            android:name=".TakeImageActivity"
            android:hardwareAccelerated="false"
            android:screenOrientation="portrait"
            android:label="@string/app_name" >
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
    </application>

</manifest>

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