Android+openCV人脸检测2(静态图片)
前几篇文章中有提到对openCV环境配置，这里再重新梳理导入和使用openCV进行简单的人脸检测（包括使用级联分类器）
一 首先导入openCVLibrary320
二 设置gradle的sdk版本号与当前项目一致
compileSdkVersion 26
buildToolsVersion "26.0.2"
defaultConfig {
minSdkVersion 14
targetSdkVersion 26
}
三 新建 jniLibs 目录
在 app/src/main 目录下 与 java 目录同级，新建 jniLibs 目录
把 OpenCV-android-sdk-3.2/sdk/native/libs 目录下的所有文件夹内容拷贝到 jniLibs 目录
四 加载so包
private static String strLibraryName = "opencv_java3"; // 不需要添加前缀 libopencv_java3 static { try { Log.e("loadLibrary", strLibraryName); System.loadLibrary(strLibraryName); //System.loadLibrary(Core.NATIVE_LIBRARY_NAME); // couldn't find "libopencv_java320.so" } catch (UnsatisfiedLinkError e) { Log.e("loadLibrary", "Native code library failed to load.\n" + e); } catch (Exception e) { Log.e("loadLibrary", "Exception: " + e); } }
五 添加xml级联分类器
在导入的openCVLibrary320模块中，找到 src/main/res 目录，新建raw文件夹。
在 OpenCV-android-sdk-3.2/sdk/etc 目录下，存放的则是训练好的分类器。把 haarcascades 目录和 lbpcascades 目录内的所有xml文件拷贝到 raw目录中。
六 配置权限
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" /> <uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE" /> <uses-permission android:name="android.permission.MOUNT_UNMOUNT_FILESYSTEMS" /> <uses-permission android:name="android.permission.CAMERA" /> <uses-permission android:name="android.permission.FLASHLIGHT" />
完成以上步骤，就可以使用opencv了。
使用openCV
首先创建检测器
mCascadeClassifier = createDetector(context, R.raw.haarcascade_frontalface_alt); /** * 创建检测器 * * @param context 上下文 * @param id 级联分类器ID * @return 检测器 */ private CascadeClassifier createDetector(Context context, int id) { CascadeClassifier javaDetector; InputStream is = null; FileOutputStream os = null; try { is = context.getResources().openRawResource(id); File cascadeDir = context.getDir("cascade", Context.MODE_PRIVATE); File cascadeFile = new File(cascadeDir, id + ".xml"); os = new FileOutputStream(cascadeFile); byte[] buffer = new byte[4096]; int bytesRead; while ((bytesRead = is.read(buffer)) != -1) { os.write(buffer, 0, bytesRead); } javaDetector = new CascadeClassifier(cascadeFile.getAbsolutePath()); if (javaDetector.empty()) { javaDetector = null; } boolean delete = cascadeDir.delete(); return javaDetector; } catch (IOException e) { e.printStackTrace(); return null; } finally { try { if (null != is) { is.close(); } if (null != os) { os.close(); } } catch (IOException e) { e.printStackTrace(); } } }
检测人脸方法：
/** * 目标检测 图片 * * @param gray 灰度图像 * @param object 识别结果的容器 * @return */ public Rect[] detectObjectImage(Mat gray, MatOfRect object) { mCascadeClassifier.detectMultiScale(gray,object); return object.toArray(); }
detectFace 整个函数：
private void detectFace() { try { // bitmapToMat Mat toMat = new Mat(); Utils.bitmapToMat(bitmap, toMat); Mat copyMat = new Mat(); toMat.copyTo(copyMat); // 复制 // togray Mat gray = new Mat(); Imgproc.cvtColor(toMat, gray, Imgproc.COLOR_RGBA2GRAY); MatOfRect mRect = new MatOfRect(); Rect[] object = mFaceDetector.detectObjectImage(gray, mRect); Log.e("objectLength", object.length + ""); int maxRectArea = 0 * 0; Rect maxRect = null; int facenum = 0; // Draw a bounding box around each face. for (Rect rect : object) { Imgproc.rectangle( toMat, new Point(rect.x, rect.y), new Point(rect.x + rect.width, rect.y + rect.height), new Scalar(255, 0, 0), 3); ++facenum; // 找出最大的面积 int tmp = rect.width * rect.height; if (tmp >= maxRectArea) { maxRectArea = tmp; maxRect = rect; } } rectBitmap = null; if (facenum != 0) { // 剪切最大的头像 Log.e("剪切的长宽", String.format("高:%s,宽:%s", maxRect.width, maxRect.height)); Rect rect = new Rect(maxRect.x, maxRect.y, maxRect.width, maxRect.height); Mat rectMat = new Mat(copyMat, rect); // 从原始图像拿 rectBitmap = Bitmap.createBitmap(rectMat.cols(), rectMat.rows(), Bitmap.Config.ARGB_8888); Utils.matToBitmap(rectMat, rectBitmap); } textView.setText(String.format("检测到%1$d个人脸", facenum)); Utils.matToBitmap(toMat, bitmap); } catch (Exception e) { e.printStackTrace(); } }
附所有代码：
package com.myproject.facedetection.ui; import android.content.Intent; import android.graphics.Bitmap; import android.graphics.BitmapFactory; import android.net.Uri; import android.os.Environment; import android.provider.MediaStore; import android.support.v7.app.AppCompatActivity; import android.os.Bundle; import android.util.Log; import android.view.Gravity; import android.view.View; import android.widget.TextView; import android.widget.Toast; import com.myproject.facedetection.R; import com.myproject.facedetection.entity.CustomImageButton; import com.opencvlib.ObjectDetector; import org.opencv.android.Utils; import org.opencv.core.Mat; import org.opencv.core.MatOfRect; import org.opencv.core.Point; import org.opencv.core.Rect; import org.opencv.core.Scalar; import org.opencv.imgproc.Imgproc; import java.io.File; public class FaceDetectionOpenCVActivity extends AppCompatActivity { private ObjectDetector mFaceDetector; private static String CAMERAIMAGENAME = "image.jpg"; private CustomImageButton imageButton; private CustomImageButton imageButton2; private TextView textView; private Bitmap bitmap; private Bitmap rectBitmap; private Bitmap resizeBitmap; private Toast toast; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_face_detection_opencv); textView = (TextView) findViewById(R.id.tv_face); imageButton = (CustomImageButton) findViewById(R.id.iv_face); imageButton.setGravity(Gravity.CENTER_HORIZONTAL | Gravity.CENTER_VERTICAL); imageButton2 = (CustomImageButton) findViewById(R.id.iv_face2); imageButton2.setGravity(Gravity.CENTER_HORIZONTAL | Gravity.CENTER_VERTICAL); mFaceDetector = new ObjectDetector(this, R.raw.haarcascade_frontalface_alt, 6, 0.2F, 0.2F, new Scalar(255, 0, 0, 255)); } /** * 点击添加照片事件 * * @param v */ public void onClick(View v) { int bt_id = v.getId(); switch (bt_id) { case R.id.addPic: // 添加照片 // 打开本地相册 Intent intent1 = new Intent(Intent.ACTION_PICK, android.provider.MediaStore.Images.Media.EXTERNAL_CONTENT_URI); startActivityForResult(intent1, 101); break; case R.id.takePhoto: // 拍照 // 打开本地相机 Intent intent2 = new Intent(android.provider.MediaStore.ACTION_IMAGE_CAPTURE); Uri imageUri = Uri.fromFile(new File(Environment.getExternalStorageDirectory(), CAMERAIMAGENAME)); intent2.putExtra(MediaStore.EXTRA_OUTPUT, imageUri); startActivityForResult(intent2, 102); break; case R.id.back: this.finish(); break; default: break; } } @Override protected void onActivityResult(int requestCode, int resultCode, Intent data) { super.onActivityResult(requestCode, resultCode, data); // 加判断 不选择照片或者不拍照时不闪退 //Log.e("data", String.valueOf(data)); //if (data == null) //return; bitmap = null; switch (requestCode) { // 选择图片库的图片 case 101: if (resultCode == RESULT_OK) { try { Uri uri = data.getData(); bitmap = MediaStore.Images.Media.getBitmap(this.getContentResolver(), uri); } catch (Exception e) { e.printStackTrace(); } } break; // 表示调用本地照相机拍照 case 102: if (resultCode == RESULT_OK) { //Bundle bundle = data.getExtras(); //bm = (Bitmap) bundle.get("data"); bitmap = BitmapFactory.decodeFile(Environment.getExternalStorageDirectory() + "/" + CAMERAIMAGENAME); } break; default: break; } Log.e("bitmap", String.valueOf(bitmap)); if (bitmap == null) { toast = Toast.makeText(FaceDetectionOpenCVActivity.this, "未选择图像", Toast.LENGTH_SHORT); toast.show(); return; } // 识别图片 并画框 detectFace(); // 将照片剪裁 bitmap将被释放重新赋值 int ibWidth = imageButton.getWidth(); int ibHeight = imageButton.getHeight(); resizeBitmap = imageButton.resizeBitmap(bitmap, ibWidth, ibHeight); imageButton.setBitmap(resizeBitmap); imageButton2.setBitmap(rectBitmap); } private void detectFace() { try { // bitmapToMat Mat toMat = new Mat(); Utils.bitmapToMat(bitmap, toMat); Mat copyMat = new Mat(); toMat.copyTo(copyMat); // 复制 // togray Mat gray = new Mat(); Imgproc.cvtColor(toMat, gray, Imgproc.COLOR_RGBA2GRAY); MatOfRect mRect = new MatOfRect(); Rect[] object = mFaceDetector.detectObjectImage(gray, mRect); Log.e("objectLength", object.length + ""); int maxRectArea = 0 * 0; Rect maxRect = null; int facenum = 0; // Draw a bounding box around each face. for (Rect rect : object) { Imgproc.rectangle( toMat, new Point(rect.x, rect.y), new Point(rect.x + rect.width, rect.y + rect.height), new Scalar(255, 0, 0), 3); ++facenum; // 找出最大的面积 int tmp = rect.width * rect.height; if (tmp >= maxRectArea) { maxRectArea = tmp; maxRect = rect; } } rectBitmap = null; if (facenum != 0) { // 剪切最大的头像 Log.e("剪切的长宽", String.format("高:%s,宽:%s", maxRect.width, maxRect.height)); Rect rect = new Rect(maxRect.x, maxRect.y, maxRect.width, maxRect.height); Mat rectMat = new Mat(copyMat, rect); // 从原始图像拿 rectBitmap = Bitmap.createBitmap(rectMat.cols(), rectMat.rows(), Bitmap.Config.ARGB_8888); Utils.matToBitmap(rectMat, rectBitmap); } textView.setText(String.format("检测到%1$d个人脸", facenum)); Utils.matToBitmap(toMat, bitmap); } catch (Exception e) { e.printStackTrace(); } } }
package com.opencvlib; import android.content.Context; import org.opencv.core.Mat; import org.opencv.core.MatOfRect; import org.opencv.core.Rect; import org.opencv.core.Scalar; import org.opencv.core.Size; import org.opencv.objdetect.CascadeClassifier; import org.opencv.objdetect.Objdetect; import java.io.File; import java.io.FileOutputStream; import java.io.IOException; import java.io.InputStream; /** * Created by think-hxr on 17-10-12. */ public class ObjectDetector { private CascadeClassifier mCascadeClassifier; private int mMinNeighbors; private float mRelativeObjectWidth; private float mRelativeObjectHeight; private Scalar mRectColor; /** * 构造方法 * * @param context 上下文 * @param id 级联分类器ID * @param minNeighbors 连续几帧确认目标 * @param relativeObjectWidth 最小宽度屏占比 * @param relativeObjectHeight 最小高度屏占比 * @param rectColor 画笔颜色 */ public ObjectDetector(Context context, int id, int minNeighbors, float relativeObjectWidth, float relativeObjectHeight, Scalar rectColor) { context = context.getApplicationContext(); mCascadeClassifier = createDetector(context, id); mMinNeighbors = minNeighbors; mRelativeObjectWidth = relativeObjectWidth; mRelativeObjectHeight = relativeObjectHeight; mRectColor = rectColor; } /** * 创建检测器 * * @param context 上下文 * @param id 级联分类器ID * @return 检测器 */ private CascadeClassifier createDetector(Context context, int id) { CascadeClassifier javaDetector; InputStream is = null; FileOutputStream os = null; try { is = context.getResources().openRawResource(id); File cascadeDir = context.getDir("cascade", Context.MODE_PRIVATE); File cascadeFile = new File(cascadeDir, id + ".xml"); os = new FileOutputStream(cascadeFile); byte[] buffer = new byte[4096]; int bytesRead; while ((bytesRead = is.read(buffer)) != -1) { os.write(buffer, 0, bytesRead); } javaDetector = new CascadeClassifier(cascadeFile.getAbsolutePath()); if (javaDetector.empty()) { javaDetector = null; } boolean delete = cascadeDir.delete(); return javaDetector; } catch (IOException e) { e.printStackTrace(); return null; } finally { try { if (null != is) { is.close(); } if (null != os) { os.close(); } } catch (IOException e) { e.printStackTrace(); } } } /** * 目标检测 视频 * * @param gray 灰度图像 * @param object 识别结果的容器 * @return 检测到的目标位置集合 */ public Rect[] detectObject(Mat gray, MatOfRect object) { // 使用Java人脸检测 mCascadeClassifier.detectMultiScale( gray, // 要检查的灰度图像 object, // 检测到的人脸 1.1, // 表示在前后两次相继的扫描中，搜索窗口的比例系数。默认为1.1即每次搜索窗口依次扩大10%; mMinNeighbors, // 默认是3 控制误检测，表示默认几次重叠检测到人脸，才认为人脸存在 Objdetect.CASCADE_SCALE_IMAGE, getSize(gray, mRelativeObjectWidth, mRelativeObjectHeight), // 目标最小可能的大小 gray.size()); // 目标最大可能的大小 return object.toArray(); } /** * 目标检测 图片 * * @param gray 灰度图像 * @param object 识别结果的容器 * @return */ public Rect[] detectObjectImage(Mat gray, MatOfRect object) { mCascadeClassifier.detectMultiScale(gray,object); return object.toArray(); } /** * 根据屏占比获取大小 * * @param gray gray * @param relativeObjectWidth 最小宽度屏占比 * @param relativeObjectHeight 最小高度屏占比 * @return 大小 */ private Size getSize(Mat gray, float relativeObjectWidth, float relativeObjectHeight) { Size size = gray.size(); int cameraWidth = gray.cols(); int cameraHeight = gray.rows(); int width = Math.round(cameraWidth * relativeObjectWidth); int height = Math.round(cameraHeight * relativeObjectHeight); size.width = 0 >= width ? 0 : (cameraWidth < width ? cameraWidth : width); // width [0, cameraWidth] size.height = 0 >= height ? 0 : (cameraHeight < height ? cameraHeight : height); // height [0, cameraHeight] return size; } /** * 获取画笔颜色 * * @return 颜色 */ public Scalar getRectColor() { return mRectColor; } }
<?xml version="1.0" encoding="utf-8"?> <android.support.constraint.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android" xmlns:app="http://schemas.android.com/apk/res-auto" xmlns:tools="http://schemas.android.com/tools" android:layout_width="match_parent" android:layout_height="match_parent" tools:context="com.myproject.facedetection.ui.FaceDetectionOpenCVActivity"> <com.myproject.facedetection.entity.CustomImageButton android:id="@+id/iv_face" android:layout_width="0dp" android:layout_height="460dp" android:layout_marginLeft="10dp" android:layout_marginRight="10dp" app:layout_constraintLeft_toLeftOf="parent" app:layout_constraintRight_toRightOf="parent" tools:layout_editor_absoluteY="10dp" /> <com.myproject.facedetection.entity.CustomImageButton android:id="@+id/iv_face2" android:layout_width="100dp" android:layout_height="100dp" android:layout_marginRight="10dp" app:layout_constraintRight_toRightOf="parent" tools:layout_editor_absoluteY="10dp" /> <TextView android:id="@+id/tv_face" android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_marginBottom="16dp" android:text="未检测到人脸" android:textColor="@color/colorAccent" app:layout_constraintBottom_toTopOf="@+id/ll1" app:layout_constraintLeft_toLeftOf="parent" app:layout_constraintRight_toRightOf="parent" /> <LinearLayout android:id="@+id/ll1" android:layout_width="0dp" android:layout_height="wrap_content" android:orientation="horizontal" app:layout_constraintBottom_toBottomOf="parent" app:layout_constraintLeft_toLeftOf="parent" app:layout_constraintRight_toRightOf="parent"> <Button android:id="@+id/takePhoto" android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_marginBottom="5dp" android:layout_weight="1" android:onClick="onClick" android:text="拍照(CV)" android:textSize="16sp" app:layout_constraintLeft_toLeftOf="parent" app:layout_constraintRight_toRightOf="parent" /> <Button android:id="@+id/addPic" android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_marginBottom="5dp" android:layout_weight="1" android:onClick="onClick" android:text="选择图片(CV)" android:textSize="16sp" app:layout_constraintLeft_toLeftOf="parent" app:layout_constraintRight_toRightOf="parent" /> <Button android:id="@+id/back" android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_marginBottom="0dp" android:layout_weight="1" android:onClick="onClick" android:text="返回(CV)" android:textSize="16sp" app:layout_constraintLeft_toLeftOf="parent" app:layout_constraintRight_toRightOf="parent" /> </LinearLayout> </android.support.constraint.ConstraintLayout>
