保存叠加图像

Question

所以我正在看这个关于如何在图片上保存叠加层的帖子。 Android 将视图保存为 jpg 或 png

我有我的代码拍摄照片并保存图像，就像该线程中的答案所建议的那样。问题是它只保存黑色背景的叠加层。实际拍摄的照片不是图像的一部分。这是我的代码：

package com.commonsware.android.skeleton;

import android.app.Activity;
import android.content.Context;
import android.content.Intent;
import android.graphics.Bitmap;
import android.graphics.Bitmap.CompressFormat;
import android.hardware.Camera;
import android.hardware.Camera.*;
import android.net.Uri;
import android.os.Bundle;
import android.os.Environment;
import android.util.Log;
import android.view.Display;
import android.view.Surface;
import android.view.SurfaceHolder;
import android.view.SurfaceView;
import android.view.View;
import android.view.Window;
import android.view.WindowManager;
import android.widget.FrameLayout;

import java.io.File;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.util.List;

// ----------------------------------------------------------------------

public class SimpleBulbActivity extends Activity {
    private Preview mPreview;
    private static final String TAG = "CameraDemo";
    FrameLayout preview;
    Camera mCamera;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);

        // Hide the window title.
        requestWindowFeature(Window.FEATURE_NO_TITLE);
        // create a File object for the parent directory
        File imageDirectory = new File(Environment.getExternalStorageDirectory() + "/SimpleBulb/");
        // Check if the directory exists
        if(!imageDirectory.exists()) {
            // have the object build the directory structure, if needed.
            imageDirectory.mkdirs();
        }
        setContentView(R.layout.main);
    }

    protected void onResume() {
        super.onResume();
        //Setup the FrameLayout with the Camera Preview Screen
        mPreview = new Preview(this);
        preview = (FrameLayout)findViewById(R.id.preview); 
        preview.addView(mPreview);
    }

    public void snap(View view) {
        mCamera.takePicture(shutterCallback, rawCallback, jpegCallback);
    }
    ShutterCallback shutterCallback = new ShutterCallback() {
      public void onShutter() {
          Log.d(TAG, "onShutter'd");
      }
    };

    PictureCallback rawCallback = new PictureCallback() {
      public void onPictureTaken(byte[] _data, Camera _camera) {
          Log.d(TAG, "onPictureTaken - raw");
      }
    };

    PictureCallback jpegCallback = new PictureCallback() {
      public void onPictureTaken(byte[] data, Camera _camera) {
          FileOutputStream outStream = null;
            try {
                // write to local sandbox file system
                // outStream =
                // CameraDemo.this.openFileOutput(String.format("%d.jpg",
                // System.currentTimeMillis()), 0);
                // Or write to sdcard
                FrameLayout view = (FrameLayout)findViewById(R.id.image);
                view.setDrawingCacheEnabled(true);
                Bitmap b = view.getDrawingCache();
                b.compress(CompressFormat.PNG, 95, new FileOutputStream(Environment.getExternalStorageDirectory() + String.format(
                        "/SimpleBulb/%d.png", System.currentTimeMillis())));
                /*outStream = new FileOutputStream(Environment.getExternalStorageDirectory() + String.format(
                        "/SimpleBulb/%d.jpeg", System.currentTimeMillis()));
                sendBroadcast(new Intent(Intent.ACTION_MEDIA_MOUNTED, Uri.parse("file://"+ Environment.getExternalStorageDirectory())));
                outStream.write(data);
                outStream.close();*/
                Log.d(TAG, "onPictureTaken - wrote bytes: " + data.length);
            } catch (FileNotFoundException e) {
                e.printStackTrace();
            } catch (IOException e) {
                e.printStackTrace();
            } finally {
            }
            Log.d(TAG, "onPictureTaken - jpeg");
      }
    };

 // ----------------------------------------------------------------------

    class Preview extends SurfaceView implements SurfaceHolder.Callback {
        SurfaceHolder mHolder;

        Preview(Context context) {
            super(context);

            // Install a SurfaceHolder.Callback so we get notified when the
            // underlying surface is created and destroyed.
            mHolder = getHolder();
            mHolder.addCallback(this);
            mHolder.setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS);
        }

        public void surfaceCreated(SurfaceHolder holder) {
            // The Surface has been created, acquire the camera and tell it where
            // to draw.
            mCamera = Camera.open();
            try {
               mCamera.setPreviewDisplay(holder);
               mCamera.setPreviewCallback(new PreviewCallback() {

                public void onPreviewFrame(byte[] data, Camera arg1) {
                    FileOutputStream outStream = null;
                    try {
                        outStream = new FileOutputStream(Environment.getExternalStorageDirectory().toString());
                        outStream.write(data);
                        outStream.close();
                        Log.d(TAG, "onPreviewFrame - wrote bytes: "
                                + data.length);
                    } catch (FileNotFoundException e) {
                        e.printStackTrace();
                    } catch (IOException e) {
                        e.printStackTrace();
                    } finally {
                    }
                    Preview.this.invalidate();
                }
            });
        } catch (IOException e) {
                mCamera.release();
                mCamera = null;
                e.printStackTrace();
            }
        }

        public void surfaceDestroyed(SurfaceHolder holder) {
            // Surface will be destroyed when we return, so stop the preview.
            // Because the CameraDevice object is not a shared resource, it's very
            // important to release it when the activity is paused.
            mCamera.stopPreview();
            mCamera.release();
            mCamera = null;
        }


        private Size getOptimalPreviewSize(List<Size> sizes, int w, int h) {
            final double ASPECT_TOLERANCE = 0.05;
            double targetRatio = (double) w / h;
            if (sizes == null) return null;

            Size optimalSize = null;
            double minDiff = Double.MAX_VALUE;

            int targetHeight = h;

            // Try to find an size match aspect ratio and size
            for (Size size : sizes) {
                double ratio = (double) size.width / size.height;
                if (Math.abs(ratio - targetRatio) > ASPECT_TOLERANCE) continue;
                if (Math.abs(size.height - targetHeight) < minDiff) {
                    optimalSize = size;
                    minDiff = Math.abs(size.height - targetHeight);
                }
            }

            // Cannot find the one match the aspect ratio, ignore the requirement
            if (optimalSize == null) {
                minDiff = Double.MAX_VALUE;
                for (Size size : sizes) {
                    if (Math.abs(size.height - targetHeight) < minDiff) {
                        optimalSize = size;
                        minDiff = Math.abs(size.height - targetHeight);
                    }
                }
            }
            return optimalSize;
        }

        public void surfaceChanged(SurfaceHolder holder, int format, int w, int h) {
            // Now that the size is known, set up the camera parameters and begin
            // the preview.
            Camera.Parameters parameters = mCamera.getParameters();

            List<Size> sizes = parameters.getSupportedPreviewSizes();
            Size optimalSize = getOptimalPreviewSize(sizes, w, h);

            Display display = ((WindowManager)getSystemService(WINDOW_SERVICE)).getDefaultDisplay();

            if(display.getRotation() == Surface.ROTATION_0)
            {
                parameters.setPreviewSize(optimalSize.height, optimalSize.width);                           
                mCamera.setDisplayOrientation(90);
            }

            if(display.getRotation() == Surface.ROTATION_90)
            {
                parameters.setPreviewSize(optimalSize.width, optimalSize.height);                         
            }

            if(display.getRotation() == Surface.ROTATION_180)
            {
                parameters.setPreviewSize(optimalSize.width, optimalSize.height);               
            }

            if(display.getRotation() == Surface.ROTATION_270)
            {
                parameters.setPreviewSize(optimalSize.width, optimalSize.height);
                mCamera.setDisplayOrientation(0);
            }

            mCamera.setParameters(parameters);
            mCamera.startPreview();
        }

    }

}

这是我的布局：

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="vertical" android:layout_width="fill_parent"
    android:layout_height="fill_parent" android:id="@+id/layout">
    <TextView android:layout_width="fill_parent"
        android:layout_height="wrap_content" android:text="SimpleBulb Vision"
        android:textSize="24sp" />

    <FrameLayout android:id="@+id/image" android:layout_weight="1" android:layout_width="fill_parent"
        android:layout_height="fill_parent">

    <FrameLayout android:id="@+id/preview"
        android:layout_weight="1" android:layout_width="fill_parent"
        android:layout_height="fill_parent">
    </FrameLayout>

    <ImageView android:id="@+id/bulb" android:src="@drawable/litbulb"
                   android:layout_width="match_parent"
                   android:layout_height="112dip" />

    </FrameLayout>

    <Button android:layout_width="match_parent"
        android:layout_height="wrap_content" android:id="@+id/buttonClick"
        android:text="Snap!" android:layout_gravity="center" android:onClick="snap"></Button>

</LinearLayout>

Answer 1

我非常高兴地说我已经弄清楚了这一点。由于某种原因，getDrawingCache() 无法抓取捕获的图像。因此，我将图像保存在 SD 卡上，将图像放回视图中，然后使用上述方法将它们保存为一个。尽管由于两次压缩图像而损失了一些质量，但效果很好。如果有人需要代码，请随时给我留言。