- 通过计算方差判断图像是否模糊
- 所需依赖
- 思路描述
- 实现前的准备
- 模板
- 模板子类
- 接口
- 工具类
- OpenCvUtil
- BmpUtil
- CameraUtil
- 布局文件
- activity_blur_detect_page.xml 界面
- dialog_blur.xml 对话框
- 实现
- 效果
- 后续修改
- 2021.10.20 - 使用匿名内部对象
- 图像加载库：Glide
在gradle.properties 文件中添加
implementation 'com.github.bumptech.glide:glide:4.12.0' annotationProcessor 'com.github.bumptech.glide:compiler:4.12.0'
-
OpenCV
下载opencv的安卓sdk并导入。
注意，Android Studio升级Artic Fox 2020 3.1 之后从import Module导入会有些问题，需要手动将sdk拖入项目中。
参考：https://stackoverflow.com/questions/68649524/opencv-android-studio-module-importing-issue
-
打开相机拍照；
-
拍照结束后计算图像方差；
-
根据预先设定的阈值判断图像是清晰还是模糊；
-
使用对话框显示判断结果。
异步调用opencv的方法很多，由于前不久尝试过使用模板实现图像质量检测的demo，所以这里也沿用之前写的模板方法。
模板 模板的重点在于，使用顶层的抽象类固定化方法的执行顺序，使得继承相同模板的对象具有相似的内部函数执行逻辑。
即，首先检查传入的图像是否有效，在执行模板子类、通过接口自定义的方法。
public abstract class DetectionTemplate {
protected Bitmap srcBitmap = null;
public final void detecting(IConstract.ICommon doAfter){
if (doCheckValid()){
System.out.println("开始检测");
doDetect();
doAfter.onDoSomething();
}else{
System.out.println("未开始检测");
}
// 钩子方法
hook();
}
protected void hook(){
}
protected abstract boolean doCheckValid();
// protected abstract void doAfterDetecting();
protected abstract void doDetect();
}
模板子类
public class BlurDetect extends DetectionTemplate{
private static final String TAG = "BlurDetect";
public double sqDev = 0.0;
public String strBlurDescribe = "";
public BlurDetect(final Bitmap bitmap){
this.srcBitmap = bitmap;
}
@Override
protected boolean doCheckValid() {
return srcBitmap != null;
}
@Override
protected void doDetect() {
// 获取标准差
sqDev = OpenCvUtil.getSquareDeviation(srcBitmap);
// 保留两位小数
sqDev = NumberUtil.reserveDecimal2(sqDev);
sqDev = (int)(sqDev*100)/100.0;
strBlurDescribe = "模糊度: " + sqDev;
Log.d(TAG, "计算结束: "+strBlurDescribe);
}
}
接口
接口不是必要的，但是将自定义的接口注入模板中可以使逻辑更清晰。
public interface IConstract {
interface ICommon{
void onDetected();
}
}
工具类
OpenCvUtil
public class OpenCvUtil {
private static final String TAG = "OpenCvUtil";
// 模糊度阈值
private static final int BLUR_THRESHOLD500 = 500;
private static final int BLUR_THRESHOLD300 = 300;
private static final int BLUR_THRESHOLD50 = 50;
private static final int BLUR_THRESHOLD15 = 15;
public static Bitmap matToBitmap(Mat mat){
Bitmap result = null;
if (mat != null){
result = Bitmap.createBitmap(mat.cols(), mat.rows(), Bitmap.Config.RGB_565);
if (result != null){
Utils.matToBitmap(mat, result);
}
}
return result;
}
public static Mat bitmapToMat(Bitmap bitmap){
Mat result = null;
Bitmap bmp32 = bitmap.copy(Bitmap.Config.RGB_565, true);
result = new Mat(bitmap.getHeight(), bitmap.getWidth(), CvType.CV_8UC2, new Scalar(0));
Utils.bitmapToMat(bmp32, result);
return result;
}
public static double getStandardDeviation(Bitmap bitmap){
double result = 0.0;
if (bitmap != null){
result = getStdDev(bitmap);
}
return result;
}
public static double getSquareDeviation(Bitmap bitmap){
double result = 0.0;
if (bitmap != null){
result = getStdDev(bitmap);
}
return result * result;
}
public static void judgeBlurByStdDev(final double st, final TextView tv,final Context context){
judgeBlurBySquDev(st*st, tv, context);
}
public static void judgeBlurBySquDev(final double sq, final TextView tv,final Context context){
tv.post(new Runnable() {
@Override
public void run() {
StringBuilder sb = new StringBuilder("模糊度: ");
double tempSt = sq;
// 标准差 -> 方差
// double tempSt = st * st;
sb.append(tempSt).append("t");
// 颜色可以自行设置
if (tempSt > BLUR_THRESHOLD500){
sb.append("清晰");
tv.setTextColor(context.getColor(R.color.colorGreen));
}else if(tempSt > BLUR_THRESHOLD300){
sb.append("不清晰");
tv.setTextColor(context.getColor(R.color.indianred));
}else if(tempSt > BLUR_THRESHOLD50){
sb.append("很不清晰 ");
tv.setTextColor(context.getColor(R.color.indianred));
}else if (tempSt > BLUR_THRESHOLD15){
sb.append("非常不清晰 ");
tv.setTextColor(context.getColor(R.color.colorYellow));
}else{
sb.append("完全看不清了 ");
tv.setTextColor(context.getColor(R.color.red));
}
Log.d(TAG, "run: "+sb);
tv.setText(sb);
}
});
}
public static Bitmap getBlurBitmap(final Bitmap srcBitmap){
Mat srcImage = bitmapToMat(srcBitmap);
Mat blurImage = new Mat();
blur(srcImage, blurImage, new Size(3, 3));
return matToBitmap(blurImage);
}
// region tool
private static double getStdDev(Bitmap bitmap) {
Mat matSrc = bitmapToMat(bitmap);
Mat mat = new Mat();
int channel = matSrc.channels();
System.out.println("getStdDev: channel = " + channel);
// 1表示图像是灰度图
if (channel != 1){
cvtColor(matSrc, mat, COLOR_BGR2GRAY);
}else{
mat = matSrc;
}
Mat lap = new Mat();
Laplacian(mat, lap, CV_64F);
MatOfDouble s = new MatOfDouble();
meanStdDev(lap, new MatOfDouble(), s);
double st = s.get(0, 0)[0];
System.out.println( "getStdDev: st = " + st);
// Log.d(TAG, "getStdDev: s.get(0,0)[0] = "+s.get(0,0)[0]);
return st;
}
// endregion
}
BmpUtil
public class BmpUtil {
public static Bitmap getBitmapFromImageView(ImageView imageView){
Bitmap result = null;
imageView.setDrawingCacheEnabled(true);
result = Bitmap.createBitmap(imageView.getDrawingCache());
imageView.setDrawingCacheEnabled(false);
return result;
}
public static void loadBitmap(final Uri uri, final ImageView imageView) {
if (null == uri) {
return;
}
Glide.with(imageView)
.load(uri)
.fitCenter()
.placeholder(R.drawable.ic_launcher_foreground)
.into(imageView);
}
public static void loadBitmap(final Bitmap bitmap, final ImageView imageView) {
if (null == bitmap) {
return;
}
Glide.with(imageView)
.load(bitmap)
.fitCenter()
.placeholder(R.drawable.ic_launcher_foreground)
.into(imageView);
}
}
CameraUtil
相机权限申请参考官方文档。
拍照 | Android 开发者 | Android Developers (google.cn)中提到：
请注意，startActivityForResult() 方法受调用 resolveActivity()（返回可处理 Intent 的第一个 Activity 组件）的条件保护。执行此检查非常重要，因为如果您使用任何应用都无法处理的 Intent 调用 startActivityForResult()，您的应用就会崩溃。所以只要结果不是 Null，就可以放心使用 Intent。
真机上可以正常运行，但是在模拟器上，这个返回值却总是为null导致相机无法打开。
为了解决这个问题，可以再加一个条件。
CameraManager cameraManager = (CameraManager) getSystemService(Context.CAMERA_SERVICE);
String[] cameraIds = cameraManager.getCameraIdList();
if (cameraIds.length > 0) {
//摄像头存在
if (cameraIds[0] != null || cameraIds[1] != null) {
isCamera = true;
}
}
检查手机是否有摄像头，当 isCamera为 true时同样跳转到拍照界面。
public class CameraUtil {
private static final String TAG = "CameraUtil";
public static final int INT_OPEN_CAMERA = 1001;
// 检查是否有摄像头
private static boolean isCamera = false;
@SuppressLint("QueryPermissionsNeeded")
public static void openCamera(Activity from){
if (!isCamera){
try {
CameraManager cameraManager = (CameraManager) from.getSystemService(Context.CAMERA_SERVICE);
String[] cameraIds = cameraManager.getCameraIdList();
if (cameraIds.length > 0) {
//摄像头存在
if (cameraIds[0] != null || cameraIds[1] != null) {
isCamera = true;
}
}
} catch (IllegalStateException | CameraAccessException e) {
e.printStackTrace();
}
}
Intent intentCamera = new Intent(MediaStore.ACTION_IMAGE_CAPTURE);
if (intentCamera.resolveActivity(from.getPackageManager()) != null || isCamera) {
from.startActivityForResult(intentCamera, INT_OPEN_CAMERA);
} else {
Log.d(TAG, "onClick: 打开失败");
}
}
}
布局文件
字体、颜色、背景图片之类的资源文件可以自行修改。
activity_blur_detect_page.xml 界面dialog_blur.xml 对话框>
实现
public class BlurDetectPageActivity extends AppCompatActivity {
private static final String TAG = "BlurDetectPageActivity";
ActivityBlurDetectPageBinding binding;
private Mat imageMat;
private baseLoaderCallback mLoaderCallback = new baseLoaderCallback(this) {
@Override
public void onManagerConnected(int status) {
switch (status) {
case LoaderCallbackInterface.SUCCESS: {
Log.i("OpenCV", "OpenCV loaded successfully");
imageMat = new Mat();
}
break;
default: {
super.onManagerConnected(status);
}
break;
}
}
};
@Override
protected void onCreate(@Nullable Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
binding = DataBindingUtil.setContentView(this, R.layout.activity_blur_detect_page);
setBtnListener();
}
private void setBtnListener() {
// 拍照
binding.btnOpenCamera.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
CameraUtil.openCamera(BlurDetectPageActivity.this);
}
});
}
@Override
protected void onResume() {
super.onResume();
if (!OpenCVLoader.initDebug()) {
Log.d("OpenCV", "Internal OpenCV library not found. Using OpenCV Manager for initialization");
OpenCVLoader.initAsync(OpenCVLoader.OPENCV_VERSION_3_0_0, this, mLoaderCallback);
} else {
Log.d("OpenCV", "OpenCV library found inside package. Using it!");
mLoaderCallback.onManagerConnected(LoaderCallbackInterface.SUCCESS);
}
}
@Override
protected void onActivityResult(int requestCode, int resultCode, @Nullable Intent data) {
super.onActivityResult(requestCode, resultCode, data);
Log.d(TAG, "onActivityResult: requestCode = " + requestCode);
Log.d(TAG, "onActivityResult: resultCode = " + resultCode);
if (resultCode == RESULT_OK) {
if (requestCode == CameraUtil.INT_OPEN_CAMERA && data != null) {
Bundle extras = data.getExtras();
Bitmap bmpCaptured = (Bitmap) extras.get("data");
// 加载位图
BmpUtil.loadBitmap(bmpCaptured, binding.ibImageShow);
// 检测模糊度
detectBlur(bmpCaptured);
}
}
}
// 检测模糊度-方差
private void detectBlur(Bitmap srcBmp) {
// 模糊度检测子对象
BlurDetect blurDetect = new BlurDetect(srcBmp);
// 耗时操作在子线程中执行，避免ANR(Application Not Responding)
new Thread(new Runnable() {
@Override
public void run() {
// 开始执行检测逻辑
blurDetect.detecting(new IConstract.ICommon() {
// 重载onDetected 方法，检测结束后执行
@Override
public void onDetected() {
// 在UI线程中更新控件
runOnUiThread(new Runnable() {
@Override
public void run() {
double sqaDev = blurDetect.sqDev;
String strDes = blurDetect.strBlurDescribe;
Log.d(TAG, "run: sq = " + sqaDev);
Log.d(TAG, "run: des = " + strDes);
// 声明弹窗控件
LayoutInflater inflater = getLayoutInflater();
View view = inflater.inflate(R.layout.activity_dialog, null);
// 根据方差判断图像是否清晰
OpenCvUtil.judgeBlurBySquDev(sqaDev, (TextView)view.findViewById(R.id.tv_describe), getApplicationContext());
// 定义弹窗
alertDialog alertDialog2 = new alertDialog.Builder(BlurDetectPageActivity.this)
.setView(view)
.setPositiveButton("保存", new DialogInterface.OnClickListener() {
@Override
public void onClick(DialogInterface dialog, int which) {
Log.d(TAG, "onClick: 开始保存");
}
})
.setNegativeButton("取消", new DialogInterface.OnClickListener() {
@Override
public void onClick(DialogInterface dialog, int which) {
Log.d(TAG, "onClick: 取消保存");
}
}).create();
alertDialog2.show();
}
});
}
});
}
}).start();
}
}
效果
模糊度检测的实现代码中
// 检测模糊度-方差
private void detectBlur(Bitmap srcBmp) {
// 模糊度检测子对象
BlurDetect blurDetect = new BlurDetect(srcBmp);
// 耗时操作在子线程中执行，避免ANR(Application Not Responding)
new Thread(new Runnable() {
@Override
public void run() {
// 开始执行检测逻辑
blurDetect.detecting(new IConstract.ICommon() {
// 重载onDetected 方法，检测结束后执行
@Override
public void onDetected() {
// 在UI线程中更新控件
runOnUiThread(new Runnable() {
@Override
public void run() {
double sqaDev = blurDetect.sqDev;
String strDes = blurDetect.strBlurDescribe;
Log.d(TAG, "run: sq = " + sqaDev);
Log.d(TAG, "run: des = " + strDes);
// ......
在blurDetect的detecting()方法中调用blurDetect的成员变量的显得比较傻气，为了试代码更加优雅，可以自定义一个匿名内部对象用来保存检测的结果。
- 首先定义一个简单的类
public class DetectResult {
public double resultNumber;
public String describe;
public DetectResult(double squareDeviation, String describe){
this.resultNumber = squareDeviation;
this.describe = describe;
}
}
- 再修改接口，在接口中传入这个这个类
interface ICommon{
void onDetected(DetectResult detectResult);
}
- 修改模板类
主要修改了抽象方法deDetect()的返回值
public abstract class DetectionTemplate {
protected Bitmap srcBitmap = null;
public final void detecting(IConstract.ICommon doAfter){
if (doCheckValid()){
System.out.println("开始检测");
// 传入检测结果(内部参数)
doAfter.onDetected(doDetect());
}else{
System.out.println("未开始检测");
}
// 钩子方法
hook();
}
protected void hook(){
}
protected abstract boolean doCheckValid();
// 返回检测结果
protected abstract DetectResult doDetect();
}
- 修改实现子类
主要移除了两个公有成员变量
public class BlurDetect extends DetectionTemplate{
private static final String TAG = "BlurDetect";
public BlurDetect(final Bitmap bitmap){
this.srcBitmap = bitmap;
}
@Override
protected boolean doCheckValid() {
return srcBitmap != null;
}
@Override
protected DetectResult doDetect() {
// 获取方差
double sqDev = OpenCvUtil.getSquareDeviation(srcBitmap);
// 保留两位小数
sqDev = NumberUtil.reserveDecimal2(sqDev);
// 描述信息
String strBlurDescribe = "检测结果: " + sqDev;
Log.d(TAG, "计算结束: "+ strBlurDescribe);
return new DetectResult(sqDev, strBlurDescribe);
}
}
- 最后是实现部分
// 模糊度检测子对象
BlurDetect blurDetect = new BlurDetect(srcBmp);
// 耗时操作在子线程中执行，避免ANR(Application Not Responding)
new Thread(new Runnable() {
@Override
public void run() {
// 开始执行检测逻辑
blurDetect.detecting(detectResult -> {
// 在UI线程中更新控件
runOnUiThread(new Runnable() {
@Override
public void run() {
double sqaDev = detectResult.resultNumber;
String strDes = detectResult.describe;
Log.d(TAG, "run: sq = " + sqaDev);
Log.d(TAG, "run: des = " + strDes);
这样子检测得到的方差和描述信息就对外隐藏了，detectResult只能在匿名函数detectResult -> {}中使用。
