zxing二维码拉伸问题

google提供的zxing二维码识别demo在有些机型上拉伸非常严重，可以通过设置SurfaceView全屏，并设置图片宽高比，预览宽高比与屏幕宽高比一致来解决，具体代码如下

只修改了CameraConfigurationManager中 getCameraResolution(Camera.Parameters parameters, Point screenResolution)方法和 setDesiredCameraParameters(Camera camera) 

/* * Copyright (C) 2010 ZXing authors * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * *      http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */package com.yagou.yggx.android.qrcode;import android.content.Context;import android.graphics.Point;import android.hardware.Camera;import android.hardware.Camera.Size;import android.os.Build;import android.util.Log;import android.view.Display;import android.view.WindowManager;import java.lang.reflect.Method;import java.util.Collections;import java.util.Comparator;import java.util.List;import java.util.regex.Pattern;import com.baidu.platform.comapi.map.s;import com.yagou.yggx.android.utils.Toast;final class CameraConfigurationManager {  private static final String TAG = CameraConfigurationManager.class.getSimpleName();  private static final int TEN_DESIRED_ZOOM = 27;  private static final int DESIRED_SHARPNESS = 30;  private static final Pattern COMMA_PATTERN = Pattern.compile(",");  private final Context context;  private Point screenResolution;  private Point cameraResolution;  private int previewFormat;  private String previewFormatString;  CameraConfigurationManager(Context context) {    this.context = context;  }  /**   * Reads, one time, values from the camera that are needed by the app.   */  void initFromCameraParameters(Camera camera) {    Camera.Parameters parameters = camera.getParameters();    previewFormat = parameters.getPreviewFormat();    previewFormatString = parameters.get("preview-format");    Log.d(TAG, "Default preview format: " + previewFormat + '/' + previewFormatString);    WindowManager manager = (WindowManager) context.getSystemService(Context.WINDOW_SERVICE);    Display display = manager.getDefaultDisplay();    screenResolution = new Point(display.getWidth(), display.getHeight());    Log.d(TAG, "Screen resolution: " + screenResolution);    cameraResolution = getCameraResolution(parameters, screenResolution);    Log.d(TAG, "Camera resolution: " + screenResolution);  }  /**   * Sets the camera up to take preview images which are used for both preview and decoding.   * We detect the preview format here so that buildLuminanceSource() can build an appropriate   * LuminanceSource subclass. In the future we may want to force YUV420SP as it's the smallest,   * and the planar Y can be used for barcode scanning without a copy in some cases.   */  void setDesiredCameraParameters(Camera camera) {    Camera.Parameters parameters = camera.getParameters();    Log.d(TAG, "Setting preview size: " + cameraResolution);    parameters.setPreviewSize(cameraResolution.x, cameraResolution.y);    setFlash(parameters);    setZoom(parameters);    //setSharpness(parameters);    //modify here    //    camera.setDisplayOrientation(90);    //����2.1    setDisplayOrientation(camera, 90);    camera.setParameters(parameters);        Size pic=getPicSize(parameters.getSupportedPictureSizes(),1.0*cameraResolution.x/cameraResolution.y);    parameters.setPictureSize(pic.width, pic.height);          pic=parameters.getPictureSize();    Size pre=parameters.getPreviewSize();    Toast.showText(context, "pic "+pic.width+"  "+pic.height+"\n pre "+pre.width+" "+pre.height, 1);  }        private Size getPicSize(List<Size> list, double d) {// TODO Auto-generated method stub   Collections.sort(list, new Comparator<Size>() {@Overridepublic int compare(Size lhs, Size rhs) {// TODO Auto-generated method stubif (lhs.width-rhs.width==0) {return lhs.height-rhs.height;}return lhs.width-rhs.width;}}); for (Size size : list) {if (Math.abs(size.width*1.0/size.height-d)<0.03) {return size;}}return list.get(0);}Point getCameraResolution() {    return cameraResolution;  }  Point getScreenResolution() {    return screenResolution;  }  int getPreviewFormat() {    return previewFormat;  }  String getPreviewFormatString() {    return previewFormatString;  }  private static Point getCameraResolution(Camera.Parameters parameters, Point screenResolution) {  System.out.println("pingmu  "+screenResolution.x+"  "+screenResolution.y); List<Size>list= parameters.getSupportedPreviewSizes(); Collections.sort(list, new Comparator<Size>() { @Overridepublic int compare(Size lhs, Size rhs) {// TODO Auto-generated method stubif (lhs.width-rhs.width==0) {return lhs.height-rhs.height;}return lhs.width-rhs.width;}}); for (Size size : list) { System.out.println(size.width+"   "+size.height);if (Math.abs(   size.width*1.0/size.height   -   1.0*screenResolution.y/screenResolution.x  )<0.1) {return new Point(size.width, size.height);} } return new Point(list.get(0).width, list.get(0).height);  //    String previewSizeValueString = parameters.get("preview-size-values");//    // saw this on Xperia//    if (previewSizeValueString == null) {//      previewSizeValueString = parameters.get("preview-size-value");//    }////    Point cameraResolution = null;////    if (previewSizeValueString != null) {//      Log.d(TAG, "preview-size-values parameter: " + previewSizeValueString);//      cameraResolution = findBestPreviewSizeValue(previewSizeValueString, screenResolution);//    }////    if (cameraResolution == null) {//      // Ensure that the camera resolution is a multiple of 8, as the screen may not be.//      cameraResolution = new Point(//          (screenResolution.x >> 3) << 3,//          (screenResolution.y >> 3) << 3);//    }////    return cameraResolution;  }  private static Point findBestPreviewSizeValue(CharSequence previewSizeValueString, Point screenResolution) {    int bestX = 0;    int bestY = 0;    int diff = Integer.MAX_VALUE;    for (String previewSize : COMMA_PATTERN.split(previewSizeValueString)) {      previewSize = previewSize.trim();      int dimPosition = previewSize.indexOf('x');      if (dimPosition < 0) {        Log.w(TAG, "Bad preview-size: " + previewSize);        continue;      }      int newX;      int newY;      try {        newX = Integer.parseInt(previewSize.substring(0, dimPosition));        newY = Integer.parseInt(previewSize.substring(dimPosition + 1));      } catch (NumberFormatException nfe) {        Log.w(TAG, "Bad preview-size: " + previewSize);        continue;      }      int newDiff = Math.abs(newX - screenResolution.x) + Math.abs(newY - screenResolution.y);      if (newDiff == 0) {        bestX = newX;        bestY = newY;        break;      } else if (newDiff < diff) {        bestX = newX;        bestY = newY;        diff = newDiff;      }    }    if (bestX > 0 && bestY > 0) {      return new Point(bestX, bestY);    }    return null;  }  private static int findBestMotZoomValue(CharSequence stringValues, int tenDesiredZoom) {    int tenBestValue = 0;    for (String stringValue : COMMA_PATTERN.split(stringValues)) {      stringValue = stringValue.trim();      double value;      try {        value = Double.parseDouble(stringValue);      } catch (NumberFormatException nfe) {        return tenDesiredZoom;      }      int tenValue = (int) (10.0 * value);      if (Math.abs(tenDesiredZoom - value) < Math.abs(tenDesiredZoom - tenBestValue)) {        tenBestValue = tenValue;      }    }    return tenBestValue;  }  private void setFlash(Camera.Parameters parameters) {    // FIXME: This is a hack to turn the flash off on the Samsung Galaxy.    // And this is a hack-hack to work around a different value on the Behold II    // Restrict Behold II check to Cupcake, per Samsung's advice    //if (Build.MODEL.contains("Behold II") &&    //    CameraManager.SDK_INT == Build.VERSION_CODES.CUPCAKE) {    if (Build.MODEL.contains("Behold II") && CameraManager.SDK_INT == 3) { // 3 = Cupcake      parameters.set("flash-value", 1);    } else {      parameters.set("flash-value", 2);    }    // This is the standard setting to turn the flash off that all devices should honor.    parameters.set("flash-mode", "off");  }  private void setZoom(Camera.Parameters parameters) {    String zoomSupportedString = parameters.get("zoom-supported");    if (zoomSupportedString != null && !Boolean.parseBoolean(zoomSupportedString)) {      return;    }    int tenDesiredZoom = TEN_DESIRED_ZOOM;    String maxZoomString = parameters.get("max-zoom");    if (maxZoomString != null) {      try {        int tenMaxZoom = (int) (10.0 * Double.parseDouble(maxZoomString));        if (tenDesiredZoom > tenMaxZoom) {          tenDesiredZoom = tenMaxZoom;        }      } catch (NumberFormatException nfe) {        Log.w(TAG, "Bad max-zoom: " + maxZoomString);      }    }    String takingPictureZoomMaxString = parameters.get("taking-picture-zoom-max");    if (takingPictureZoomMaxString != null) {      try {        int tenMaxZoom = Integer.parseInt(takingPictureZoomMaxString);        if (tenDesiredZoom > tenMaxZoom) {          tenDesiredZoom = tenMaxZoom;        }      } catch (NumberFormatException nfe) {        Log.w(TAG, "Bad taking-picture-zoom-max: " + takingPictureZoomMaxString);      }    }    String motZoomValuesString = parameters.get("mot-zoom-values");    if (motZoomValuesString != null) {      tenDesiredZoom = findBestMotZoomValue(motZoomValuesString, tenDesiredZoom);    }    String motZoomStepString = parameters.get("mot-zoom-step");    if (motZoomStepString != null) {      try {        double motZoomStep = Double.parseDouble(motZoomStepString.trim());        int tenZoomStep = (int) (10.0 * motZoomStep);        if (tenZoomStep > 1) {          tenDesiredZoom -= tenDesiredZoom % tenZoomStep;        }      } catch (NumberFormatException nfe) {        // continue      }    }    // Set zoom. This helps encourage the user to pull back.    // Some devices like the Behold have a zoom parameter    if (maxZoomString != null || motZoomValuesString != null) {      parameters.set("zoom", String.valueOf(tenDesiredZoom / 10.0));    }    // Most devices, like the Hero, appear to expose this zoom parameter.    // It takes on values like "27" which appears to mean 2.7x zoom    if (takingPictureZoomMaxString != null) {      parameters.set("taking-picture-zoom", tenDesiredZoom);    }  }public static int getDesiredSharpness() {return DESIRED_SHARPNESS;}/** * compatible  1.6 * @param camera * @param angle */protected void setDisplayOrientation(Camera camera, int angle){          Method downPolymorphic;          try          {              downPolymorphic = camera.getClass().getMethod("setDisplayOrientation", new Class[] { int.class });              if (downPolymorphic != null)                  downPolymorphic.invoke(camera, new Object[] { angle });          }          catch (Exception e1)          {          }     }  }