android手机拍照功能的实现及原理.doc

android手机拍照功能的实现及原理 [html]?view plaincopy -------------------------------------------------------------------?? 在main.xml布局文件添加用于显示取景画面的SurfaceView?控件：?? SurfaceView?android:layout_width=fill_parent?android:layout_height=240dip?android:id=@+id/surfaceView?/?? SurfaceView?surfaceView?=?(SurfaceView)this.findViewById(R.id.surfaceView);?? surfaceView.getHolder().setFixedSize(176,?144);?//设置分辨率?? /*下面设置Surface不维护自己的缓冲区，而是等待屏幕的渲染引擎将内容推送到用户面前*/?? surfaceView.getHolder().setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS);?? Camera?camera?=?Camera.open();?? WindowManager?wm?=?(WindowManager)?getSystemService(Context.WINDOW_SERVICE);?? Display?display?=?wm.getDefaultDisplay();?? Camera.Parameters?parameters?=?camera.getParameters();?? parameters.setPreviewSize(display.getWidth(),?display.getHeight());//设置预览照片的大小?? parameters.setPreviewFrameRate(3);//每秒3帧?? parameters.setPictureFormat(PixelFormat.JPEG);//设置照片的输出格式?? parameters.set(jpeg-quality,?85);//照片质量?? parameters.setPictureSize(display.getWidth(),?display.getHeight());//设置照片的大小?? camera.setParameters(parameters);?? camera.setPreviewDisplay(surfaceView.getHolder());//通过SurfaceView显示取景画面?? camera.startPreview();//开始预览?? camera.autoFocus(null);//自动对焦?? camera.takePicture(null,?null,?null,?jpegCallback);//拍照片?? camera.stopPreview();//停止预览?? camera.release();//释放摄像头?? -------------------------------------------------------------------------?? uses-permission?android:name=android.permission.CAMERA/?? package cn.itcast.picture; import java.io.File;import java.io.FileOutputStream; import android.app.Activity;import android.content.Context;import android.graphics.Bitmap;import android.graphics.BitmapFactory;import android.graphics.PixelFormat;import android.graphics.Bitmap.CompressFormat;import android.hardware.Camera;import android.os.Bundle;import android.os.Environment;import android.util.Log;import android.view.Display;import android.view.KeyEvent;import android.view.SurfaceHolder;import android.view.SurfaceView;