安卓相机图像尺寸

Question

在我的应用程序中，我使用相机类运行代码拍照，但它给出的图像尺寸为2048 x 1536像素。

当我使用我的Android设备的默认相机时，它会给我2048 x 1232像素的图像大小。

现在问题是，我该如何使我的应用程序在拍摄照片时给我与默认相机相同的图像尺寸（即2048 x 1232）？

我有以下代码：

CameraActivity.java

public class CameraActivity extends Activity {
    private static final String TAG = "CameraDemo";
    Preview preview; // <1>
    FrameLayout buttonClick; // <2>

    /** Called when the activity is first created. */
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.camera);

        Toast.makeText(getBaseContext(), "Touch the screen to take picture.", Toast.LENGTH_SHORT).show();

        preview = new Preview(this); // <3>
        ((FrameLayout) findViewById(R.id.preview)).addView(preview); // <4>

        //buttonClick = (Button) findViewById(R.id.buttonClick);

        buttonClick = (FrameLayout) findViewById(R.id.preview);

        buttonClick.setOnClickListener(new OnClickListener() {
            public void onClick(View v) { // <5>
                preview.camera.takePicture(shutterCallback, rawCallback, jpegCallback);
            }
        });

        Log.d(TAG, "onCreate'd");
    }

    // Called when shutter is opened
    ShutterCallback shutterCallback = new ShutterCallback() { // <6>
        public void onShutter() {
            Log.d(TAG, "onShutter'd");
        }
    };

    //Handles data for raw picture
    PictureCallback rawCallback = new PictureCallback() { // <7>
        public void onPictureTaken(byte[] data, Camera camera) {
            Log.d(TAG, "onPictureTaken - raw");
        }
    };


    // Handles data for jpeg picture
    PictureCallback jpegCallback = new PictureCallback() { // <8>
        public void onPictureTaken(byte[] data, Camera camera) {


            FileOutputStream outStream = null;
            try {

                //Write to SD Card
                outStream = new FileOutputStream(
                    String.format(
                            Environment.getExternalStorageDirectory() + "/Engagia/AudienceImages/" + CameraActivity.this.sessionNumber + ".jpg",
                            System.currentTimeMillis()
                    )); // <9>

                outStream.write(data);
                outStream.close();

                Toast.makeText(getBaseContext(), "Preview", Toast.LENGTH_SHORT).show();


                Log.d(TAG, "onPictureTaken - wrote bytes: " + data.length);
            } catch (FileNotFoundException e) { // <10>
                e.printStackTrace();
            } catch (IOException e) {
                e.printStackTrace();
            } finally {

            }
            Log.d(TAG, "onPictureTaken - jpeg");
        }
    };
}

Preview.java

(Note: This is a title or heading and does not require translation.)

package com.first.Engagia;

import java.io.IOException;

import android.content.Context;
import android.hardware.Camera;
import android.hardware.Camera.PreviewCallback;
import android.util.Log;
import android.view.SurfaceHolder;
import android.view.SurfaceView;

class Preview extends SurfaceView implements SurfaceHolder.Callback { // <1>
    private static final String TAG = "Preview";

    SurfaceHolder mHolder;  // <2>
    public Camera camera; // <3>

    Preview(Context context) {
        super(context);

        // Install a SurfaceHolder.Callback so we get notified when the
        // underlying surface is created and destroyed.
        mHolder = getHolder();  // <4>
        mHolder.addCallback(this);  // <5>
        mHolder.setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS); // <6>
    }


    //Called once the holder is ready
    public void surfaceCreated(SurfaceHolder holder) {  // <7>
        // The Surface has been created, acquire the camera and tell it where
        // to draw.
        camera = Camera.open(); // <8>
        try {
            camera.setPreviewDisplay(holder);  // <9>

            camera.setPreviewCallback(new PreviewCallback() { // <10>

                // Called for each frame previewed
                public void onPreviewFrame(byte[] data, Camera camera) {  // <11>
                    Log.d(TAG, "onPreviewFrame called at: " + System.currentTimeMillis());
                    Preview.this.invalidate();  // <12>
                }

            });
        } catch (IOException e) { // <13>
            e.printStackTrace();
        }
    }

  // Called when the holder is destroyed
  public void surfaceDestroyed(SurfaceHolder holder) {  // <14>
    camera.stopPreview();
    camera = null;
  }

  // Called when holder has changed
  public void surfaceChanged(SurfaceHolder holder, int format, int w, int h) { // <15>
    camera.startPreview();
  }

}

Main.xml:

<?xml version="1.0" encoding="utf-8"?>
<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:id="@+id/preview" 
android:layout_width="match_parent"
android:layout_height="match_parent" >

<Button android:layout_width="wrap_content"
android:layout_height="wrap_content" android:id="@+id/buttonClick"
android:text="Click"
android:layout_gravity="right|bottom" />

</FrameLayout>

- Emkey

Answer 1

你可以使用相机参数对象中的setPictureSize()来配置捕获的大小： http://developer.android.com/reference/android/hardware/Camera.Parameters.html#setPictureSize(int, int)

通常，首先应调用getSupportedPictureSizes()以确保你正在请求硬件支持的分辨率，但听起来你已经知道这些尺寸了。

- mikerowehl

Answer 2

将以下代码放置：

放置此代码

Parameters parameters = camera.getParameters();
parameters.set("jpeg-quality", 70);
parameters.setPictureFormat(PixelFormat.JPEG);
parameters.setPictureSize(2048, 1232);
camera.setParameters(parameters);

在您的surfaceCreated函数中，调用之后：

camera = Camera.open();

你已经找到了解决方案...

- Deepak Swami

---

你应该只使用从getSupportedPictureSizes()获取的可用照片尺寸。其他尺寸可能会导致应用程序崩溃。我亲眼见过这种情况。 - Eric Schlenz

硬编码图片尺寸是个坏主意：如果手机不支持该图片尺寸，很可能会崩溃。我们动态设置图片和预览尺寸，即使这样，我们仍然存在跨设备问题。 - AgentKnopf

Answer 3

中 点击这里

点此处。

在我的工作中，我遇到了同样的问题。 我使用这个方法解决了我的问题。

例如，我在我的SurfaceView（CameraPreview）中使用了undercode。

        Camera.Parameters parameters = camera.getParameters();
        pictureSize = MyCamPara.getInstance().getPictureSize(
                parameters.getSupportedPictureSizes(), 800);
        previewSize = MyCamPara.getInstance().getPreviewSize(
                parameters.getSupportedPreviewSizes(), getHeight());
        if (previewSize != null)
            parameters
                    .setPreviewSize(previewSize.width, previewSize.height);
        if (pictureSize != null)
            parameters
                    .setPictureSize(pictureSize.width, pictureSize.height);
        camera.setPreviewDisplay(holder);
        camera.setParameters(parameters);
        camera.startPreview();

- 許雅婷