我正在构建一个相机应用程序，但是当我拍摄照片时，它的质量非常低。
以下是我的MyCameraActivity.java的代码
我似乎无法提高质量，我已经浏览了本网站上的其他解决方案，但它们似乎对我不起作用。
质量约为177 x 144像素，我的手机能够达到3mp。
package com.laveshpillay.laveshcamera;
import java.io.File;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.text.SimpleDateFormat;
import java.util.Date;
import java.util.List;
import android.app.Activity;
import android.app.AlertDialog;
import android.content.Context;
import android.content.DialogInterface;
import android.content.Intent;
import android.content.pm.PackageManager;
import android.hardware.Camera;
import android.hardware.Camera.PictureCallback;
import android.media.CamcorderProfile;
import android.media.MediaRecorder;
import android.net.Uri;
import android.os.AsyncTask;
import android.os.Bundle;
import android.os.Environment;
import android.provider.MediaStore;
import android.util.Log;
import android.view.View;
import android.view.ViewGroup.LayoutParams;
import android.widget.Button;
import android.widget.FrameLayout;
import android.widget.LinearLayout;
import android.widget.Toast;
import com.example.mycamera.R;
public class MyCameraActivity extends Activity {
// Use constants above API 11 (MediaStore.Files.FileColumns)
protected static final int MEDIA_TYPE_IMAGE = 0;
protected static final int MEDIA_TYPE_VIDEO = 1;
private static final int CAPTURE_IMAGE_ACTIVITY_REQ = 100;
private static final String TAG = "MCAct";
private Uri fileUri;
private Camera camera;
private CameraPreview preview;
private MediaRecorder mr;
private Button videoButton;
protected boolean isRecording = false;
/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
if (!checkCameraExists(this)) {
Toast.makeText(this, "Sorry: you have no camera!", Toast.LENGTH_LONG);
finish();
}
camera = getCameraInstance();
setUpLayout();
}
// Method required if setting up an Intent button
// to call the built-in camera
protected void onActivityResult(int requestCode, int resultCode,
Intent data) {
if (requestCode == CAPTURE_IMAGE_ACTIVITY_REQ) {
if (resultCode == RESULT_OK) {
if (data == null) {
// A known bug here! The image should have saved in fileUri
Toast.makeText(this, "Image saved successfully",
Toast.LENGTH_LONG).show();
} else {
Toast.makeText(this, "Image saved successfully in: "
+ data.getData(), Toast.LENGTH_LONG).show();
}
} else if (resultCode == RESULT_CANCELED) {
// User cancelled the operation; do nothing
} else {
Toast.makeText(this, "Callout for image capture failed!",
Toast.LENGTH_LONG).show();
}
}
}
protected void onPause() {
releaseMediaRecorder();
releaseCamera();
super.onPause();
}
protected void onResume() {
if (camera == null) {
camera = getCameraInstance();
setUpLayout();
}
super.onResume();
}
protected Uri getOutputMediaFileUri(int type) {
return Uri.fromFile(getOutputMediaFile(type));
}
protected boolean prepareForVideoRecording() {
camera.unlock();
mr = new MediaRecorder();
mr.setCamera(camera);
mr.setAudioSource(MediaRecorder.AudioSource.CAMCORDER);
mr.setVideoSource(MediaRecorder.VideoSource.CAMERA);
mr.setProfile(CamcorderProfile.get(CamcorderProfile.QUALITY_HIGH));
mr.setOutputFile(getOutputMediaFile(MEDIA_TYPE_VIDEO).toString());
mr.setPreviewDisplay(preview.getHolder().getSurface());
try {
mr.prepare();
} catch (IllegalStateException e) {
Log.e(TAG, "IllegalStateException when preparing MediaRecorder "
+ e.getMessage());
e.getStackTrace();
releaseMediaRecorder();
return false;
} catch (IOException e) {
Log.e(TAG, "IllegalStateException when preparing MediaRecorder "
+ e.getMessage());
e.getStackTrace();
releaseMediaRecorder();
return false;
}
return true;
}
private boolean checkCameraExists(Context c) {
if (c.getPackageManager().hasSystemFeature(PackageManager.FEATURE_CAMERA)) {
return true;
} else {
return false;
}
}
private Camera getCameraInstance() {
Camera c = null;
try {
c = Camera.open();
} catch (Exception e) {
Log.e(TAG, "No camera: exception " + e.getMessage());
e.getStackTrace();
Toast.makeText(this, "Sorry: I can't get a camera!", Toast.LENGTH_LONG);
finish();
}
return c;
}
private void getImage() {
PictureCallback picture = new PictureCallback() {
public void onPictureTaken(byte[] data, Camera cam) {
new SaveImageTask().execute(data);
camera.startPreview();
}
};
camera.takePicture(null, null, picture);
}
private File getOutputMediaFile(int type) {
// good location for shared pictures; will not be lost if app uninstalled
File directory = new File(Environment.getExternalStoragePublicDirectory(
Environment.DIRECTORY_PICTURES), getPackageName());
if (!directory.exists()) {
if (!directory.mkdirs()) {
Log.e(TAG, "Failed to create storage directory.");
return null;
}
}
String timeStamp = new SimpleDateFormat("yyyMMdd_HHmmss")
.format(new Date());
File file;
if (type == MEDIA_TYPE_IMAGE) {
file = new File(directory.getPath() + File.separator + "IMG_"
+ timeStamp + ".jpg");
} else if (type == MEDIA_TYPE_VIDEO) {
file = new File(directory.getPath() + File.separator + "VID_"
+ timeStamp + ".mp4");
} else {
return null;
}
return file;
}
private void releaseCamera() {
if (camera != null) {
camera.stopPreview();
camera.release();
camera = null;
preview = null;
}
}
private void releaseMediaRecorder() {
if (mr != null) {
mr.reset();
mr.release();
mr = null;
camera.lock();
}
}
private void setUpLayout() {
setContentView(R.layout.activity_main);
preview = new CameraPreview(this, camera);
FrameLayout frame = (FrameLayout) findViewById(R.id.camera_preview);
frame.addView(preview);
Button captureButton = (Button) findViewById(R.id.button_capture);
captureButton.setOnClickListener(
new View.OnClickListener() {
public void onClick(View v) {
getImage();
}
}
);
setUpFlashButton();
setUpIntentButton();
setUpVideoButton();
}
private void setUpFlashButton() {
final Camera.Parameters params = camera.getParameters();
final List<String> flashList = params.getSupportedFlashModes();
if (flashList == null) {
// no flash!
return;
}
final CharSequence[] flashCS = flashList.toArray(
new CharSequence[flashList.size()]);
AlertDialog.Builder builder = new AlertDialog.Builder(this);
builder.setTitle("Choose flash type");
builder.setSingleChoiceItems(flashCS, -1,
new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog, int which) {
params.setFlashMode(flashList.get(which));
camera.setParameters(params);
Toast.makeText(getApplicationContext(), params.getFlashMode(),
Toast.LENGTH_SHORT).show();
dialog.dismiss();
}
});
final AlertDialog alert = builder.create();
Button flashButton = new Button(this);
setUpButton(flashButton, "Flash");
flashButton.setOnClickListener(
new View.OnClickListener() {
public void onClick(View v) {
alert.show();
}
}
);
}
private void setUpIntentButton() {
Button intentButton = new Button(this);
setUpButton(intentButton, "Built-in");
intentButton.setOnClickListener(
new View.OnClickListener() {
public void onClick(View v) {
Intent i = new Intent(MediaStore.ACTION_IMAGE_CAPTURE);
fileUri = getOutputMediaFileUri(MEDIA_TYPE_IMAGE);
Log.v(TAG, "fileUri: " + fileUri);
i.putExtra(MediaStore.EXTRA_OUTPUT, fileUri);
startActivityForResult(i, CAPTURE_IMAGE_ACTIVITY_REQ);
}
}
);
}
private void setUpVideoButton() {
videoButton = new Button(this);
setUpButton(videoButton, "Video");
videoButton.setOnClickListener(
new View.OnClickListener() {
public void onClick(View v) {
if (isRecording) {
mr.stop();
releaseMediaRecorder();
camera.lock();
videoButton.setText("Start video");
isRecording = false;
} else {
if (prepareForVideoRecording()) {
mr.start();
videoButton.setText("Stop video");
isRecording = true;
} else {
// Something has gone wrong! Release the camera
releaseMediaRecorder();
Toast.makeText(MyCameraActivity.this,
"Sorry: couldn't start video",
Toast.LENGTH_LONG).show();
}
}
}
}
);
}
private void setUpButton(Button button, String label) {
LinearLayout lin = (LinearLayout) findViewById(R.id.buttonlayout);
button.setText(label);
button.setLayoutParams(new LayoutParams(LayoutParams.WRAP_CONTENT,
LayoutParams.WRAP_CONTENT));
lin.addView(button);
}
class SaveImageTask extends AsyncTask<byte[], String, String> {
@Override
protected String doInBackground(byte[]... data) {
File picFile = getOutputMediaFile(MEDIA_TYPE_IMAGE);
if (picFile == null) {
Log.e(TAG, "Error creating media file; are storage permissions correct?");
return null;
}
try {
FileOutputStream fos = new FileOutputStream(picFile);
fos.write(data[0]);
fos.close();
} catch (FileNotFoundException e) {
Log.e(TAG, "File not found: " + e.getMessage());
e.getStackTrace();
} catch (IOException e) {
Log.e(TAG, "I/O error with file: " + e.getMessage());
e.getStackTrace();
}
return null;
}
}
}
PS。如果有人可以帮我改变图片以便在我的画廊中展示，我会很感激。
就这样，你知道。我是Android开发的新手
答案 0 :(得分：0)
检查此课程。调用getPickImageIntent来创建选择器意图，并在收到getImageFromResult的结果调用时。