自定义相机的画质不佳

Posted 2023-04-17

【中文标题】自定义相机的画质不佳

【英文标题】：Poor picture quality from Custom Camera

【发布时间】：2014-11-12 15:08:13

【问题描述】：

目前我正在使用自定义相机应用程序，预览看起来还不错。但是当我拍照并在我的其他活动中显示它时，图片减少了大约 80%。任何人都知道为什么会这样？画廊的质量也很差。 我正在使用来自 android 的 Camera API Demo。

我的参数：

public void surfaceChanged(SurfaceHolder holder, int format, int w, int h) 
    parameters = mCamera.getParameters();


    parameters.setPreviewSize(mPreviewSize.width, mPreviewSize.height);
    parameters.setFlashMode(Parameters.FLASH_MODE_AUTO);
    parameters.setFocusMode(Camera.Parameters.FOCUS_MODE_CONTINUOUS_PICTURE);
    parameters.setJpegQuality(100);
    parameters.setPreviewSize(mPreviewSize.width, mPreviewSize.height);
    parameters.setRotation(90);
    Display display = ((WindowManager) getContext().getSystemService(Context.WINDOW_SERVICE)).getDefaultDisplay();
    if (display.getRotation() == Surface.ROTATION_0) 
        mCamera.setDisplayOrientation(90);
     else if (display.getRotation() == Surface.ROTATION_270) 
        mCamera.setDisplayOrientation(180);
    

    mCamera.setParameters(parameters);

    mCamera.startPreview();

代码保存图片：

private PictureCallback mPicture = new PictureCallback() 
    private String TAG = "DocsPro";

    @Override
    public void onPictureTaken(byte[] data, Camera camera) 

        File pictureFile = getOutputMediaFile(MEDIA_TYPE_IMAGE);
        if (pictureFile == null) 
            Log.d(TAG, "Error creating media file, check storage permissions : PICTURE FILE IS NULL");
            return;
        

        try 
            FileOutputStream fos = new FileOutputStream(pictureFile);
            fos.write(data);
            fos.close();
            String filepath = pictureFile.getAbsolutePath();
            Intent edit = new Intent(TakePhoto.this, EditPhoto.class);
            edit.putExtra("filepath", filepath);
            startActivity(edit);
            finish();
         catch (FileNotFoundException e) 
            Log.d(TAG, "File not found: " + e.getMessage());
         catch (IOException e) 
            Log.d(TAG, "Error accessing file: " + e.getMessage());
        
    
;

private static File getOutputMediaFile(int type) 
    // To be safe, you should check that the SDCard is mounted
    // using Environment.getExternalStorageState() before doing this.

    File mediaStorageDir = new File(Environment.getExternalStoragePublicDirectory(
            Environment.DIRECTORY_PICTURES), "DocsPro");
    // This location works best if you want the created images to be shared
    // between applications and persist after your app has been uninstalled.

    // Create the storage directory if it does not exist
    if (!mediaStorageDir.exists()) 
        if (!mediaStorageDir.mkdirs()) 
            Log.d("MyCameraApp", "failed to create directory");
            return null;
        
    

    // Create a media file name
    String timeStamp = new SimpleDateFormat("yyyyMMdd_HHmmss").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;

【问题讨论】：

张贴您将图像保存到磁盘的代码

完成，请看原帖

完全未实现的建议-使用异步任务将图像字节写入磁盘reference for writing camera image on to the disk

图片的宽高尺寸是多少？

它已更改为 1944x2592，因为在其中添加了一些新代码。但是它太大了，所以我必须重新调整它才能看到我的新质量。

【参考方案1】：

问题已解决： 我只是把它放在我的预览课上改变的表面上。

 List<Camera.Size> sizes = parameters.getSupportedPictureSizes();
    Camera.Size size = sizes.get(0);
    for(int i=0;i<sizes.size();i++)
    
        if(sizes.get(i).width > size.width)
            size = sizes.get(i);
    
    parameters.setPictureSize(size.width, size.height);

然后只调整位图的大小，因为图片太大了：

    imageView = (ImageView) findViewById(R.id.Image);
    Bitmap bp = BitmapFactory.decodeFile(imagePath);
    Bitmap resized = Bitmap.createScaledBitmap(bp,(int)(bp.getWidth()*0.7), (int)(bp.getHeight()*0.7), true);
    imageView.setImageBitmap(resized);

【讨论】：

感谢为我工作。我捕获的图像现在非常清晰。还要获得相机的清晰预览 params.setFocusMode(Camera.Parameters.FOCUS_MODE_CONTINUOUS_PICTURE);见链接Auto Focus preview