Android相机教程(使用surfaceview)
Android相机教程(使用surfaceview)
提问于 2012-09-05 11:06:40
下面是我的示例代码：
package newslab.video.server;
import android.app.Activity;
import android.hardware.Camera;
import android.os.Bundle;
import android.util.Log;
import android.view.SurfaceHolder;
import android.view.SurfaceView;
import android.view.View;
import android.widget.Button;
import android.widget.TextView;
public class VideoServer extends Activity implements SurfaceHolder.Callback {
TextView testView;
Camera camera;
SurfaceView surfaceView;
SurfaceHolder surfaceHolder;
private final String tag = "VideoServer";
Button start, stop;
/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
start = (Button)findViewById(R.id.btn_start);
start.setOnClickListener(new Button.OnClickListener() {
public void onClick(View arg0) {
start_camera();
}
});
stop = (Button)findViewById(R.id.btn_stop);
stop.setOnClickListener(new Button.OnClickListener() {
public void onClick(View arg0) {
stop_camera();
}
});
surfaceView = (SurfaceView)findViewById(R.id.surfaceView1);
surfaceHolder = surfaceView.getHolder();
surfaceHolder.addCallback(this);
surfaceHolder.setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS);
}
private void start_camera() {
try{
camera = Camera.open();
}catch(RuntimeException e){
Log.e(tag, "init_camera: " + e);
return;
}
Camera.Parameters param;
param = camera.getParameters();
//modify parameter
param.setPreviewFrameRate(20);
param.setPreviewSize(176, 144);
camera.setParameters(param);
try {
camera.setPreviewDisplay(surfaceHolder);
camera.startPreview();
} catch (Exception e) {
Log.e(tag, "init_camera: " + e);
return;
}
}
private void stop_camera() {
camera.stopPreview();
camera.release();
}
public void surfaceChanged(SurfaceHolder arg0, int arg1, int arg2, int arg3) {
// TODO Auto-generated method stub
}
public void surfaceCreated(SurfaceHolder holder) {
// TODO Auto-generated method stub
}
public void surfaceDestroyed(SurfaceHolder holder) {
// TODO Auto-generated method stub
}
}但是，它只显示预览并停止相机。
有没有其他的教程可以教你进一步的处理，比如如何保存图像或者用位图处理图像？
回答 5
Stack Overflow用户
回答已采纳
发布于 2012-09-05 12:03:38
好的。因此，以下是解决方案：
我不会添加任何try catch。这只是为了捕获图像并将其存储到SD卡中。
public class VideoServer extends Activity implements SurfaceHolder.Callback {
TextView testView;
Camera camera;
SurfaceView surfaceView;
SurfaceHolder surfaceHolder;
PictureCallback rawCallback;
ShutterCallback shutterCallback;
PictureCallback jpegCallback;
private final String tag = "VideoServer";
Button start, stop, capture;
/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
start = (Button)findViewById(R.id.btn_start);
start.setOnClickListener(new Button.OnClickListener()
{
public void onClick(View arg0) {
start_camera();
}
});
stop = (Button)findViewById(R.id.btn_stop);
capture = (Button) findViewById(R.id.capture);
stop.setOnClickListener(new Button.OnClickListener()
{
public void onClick(View arg0) {
stop_camera();
}
});
capture.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View v) {
// TODO Auto-generated method stub
captureImage();
}
});
surfaceView = (SurfaceView)findViewById(R.id.surfaceView1);
surfaceHolder = surfaceView.getHolder();
surfaceHolder.addCallback(this);
surfaceHolder.setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS);
rawCallback = new PictureCallback() {
public void onPictureTaken(byte[] data, Camera camera) {
Log.d("Log", "onPictureTaken - raw");
}
};
/** Handles data for jpeg picture */
shutterCallback = new ShutterCallback() {
public void onShutter() {
Log.i("Log", "onShutter'd");
}
};
jpegCallback = new PictureCallback() {
public void onPictureTaken(byte[] data, Camera camera) {
FileOutputStream outStream = null;
try {
outStream = new FileOutputStream(String.format(
"/sdcard/%d.jpg", System.currentTimeMillis()));
outStream.write(data);
outStream.close();
Log.d("Log", "onPictureTaken - wrote bytes: " + data.length);
} catch (FileNotFoundException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
} finally {
}
Log.d("Log", "onPictureTaken - jpeg");
}
};
}
private void captureImage() {
// TODO Auto-generated method stub
camera.takePicture(shutterCallback, rawCallback, jpegCallback);
}
private void start_camera()
{
try{
camera = Camera.open();
}catch(RuntimeException e){
Log.e(tag, "init_camera: " + e);
return;
}
Camera.Parameters param;
param = camera.getParameters();
//modify parameter
param.setPreviewFrameRate(20);
param.setPreviewSize(176, 144);
camera.setParameters(param);
try {
camera.setPreviewDisplay(surfaceHolder);
camera.startPreview();
//camera.takePicture(shutter, raw, jpeg)
} catch (Exception e) {
Log.e(tag, "init_camera: " + e);
return;
}
}
private void stop_camera()
{
camera.stopPreview();
camera.release();
}
public void surfaceChanged(SurfaceHolder arg0, int arg1, int arg2, int arg3) {
// TODO Auto-generated method stub
}
public void surfaceCreated(SurfaceHolder holder) {
// TODO Auto-generated method stub
}
public void surfaceDestroyed(SurfaceHolder holder) {
// TODO Auto-generated method stub
}
}不要在start之前按下caputure按钮，因为我没有选中它。我只是想向您展示如何捕获图像并将其存储到SD卡中。
Stack Overflow用户
发布于 2012-09-05 13:02:00
别忘了在Android Manifest文件中获取摄像头的使用权限。
<uses-permission android:name="android.permission.CAMERA" ></uses-permission>此外，您还必须获得在SD卡上存储图像的许可，
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"></uses-permission>Stack Overflow用户
发布于 2017-03-20 13:53:39
manifiest文件中的摄像头权限：
<uses-feature android:name="android.hardware.camera" />
<uses-permission android:name="android.permission.CAMERA" />在manifiest文件中存储来自sdcard的图片的权限：
<uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE" />
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />页面原文内容由Stack Overflow提供。腾讯云小微IT领域专用引擎提供翻译支持
原文链接：
https://stackoverflow.com/questions/12273976
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