zxing二维码拉伸问题
google提供的zxing二维码识别demo在有些机型上拉伸很严重，能够通过设置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。详细代码例如以下
仅仅改动了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>() {
@Override
public int compare(Size lhs, Size rhs) {
// TODO Auto-generated method stub
if (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>() {
@Override
public int compare(Size lhs, Size rhs) {
// TODO Auto-generated method stub
if (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)
{
}
}
}
