摘要: OpenCv 對于圖檔有很多的處理方式,現在我想要實作倆張圖檔的比對。 首先要知道做個需要那些步驟: (1)加載倆張圖檔 (2)将兩張圖檔轉換為Mat矩陣 (3)把Mat矩陣的type轉換為Cv_8uc1類型,然後轉換為Cv_32F, 因為在c++代碼中會判斷他的類型。
OpenCv 對于圖檔有很多的處理方式,現在我想要實作倆張圖檔的比對。
首先要知道做個需要那些步驟:
(1)加載倆張圖檔
(2)将兩張圖檔轉換為Mat矩陣
(3)把Mat矩陣的type轉換為Cv_8uc1類型,然後轉換為Cv_32F,
因為在c++代碼中會判斷他的類型。
(4)通過OpenCv 來進行倆個矩陣的比較(倆個矩陣必須一樣大小的高寬)
我使用的比較類型是Imgproc.CV_COMP_CORREL,
double target = Imgproc.compareHist(mat, mat2, Imgproc.CV_COMP_CORREL);
這個target的值越大那麼也就是說相似度越高,如果完全一樣就是1.0 。
效果圖:
思路就是這樣,看看代碼的實作:
package com.example.opencv_comparepic;
import java.util.Arrays;
import org.opencv.android.BaseLoaderCallback;
import org.opencv.android.OpenCVLoader;
import org.opencv.android.Utils;
import org.opencv.core.Core;
import org.opencv.core.CvType;
import org.opencv.core.Mat;
import org.opencv.core.MatOfFloat;
import org.opencv.core.MatOfInt;
import org.opencv.core.Point;
import org.opencv.core.Rect;
import org.opencv.core.Scalar;
import org.opencv.core.Size;
import org.opencv.imgproc.Imgproc;
import android.os.Bundle;
import android.app.Activity;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.util.Log;
import android.view.Menu;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.ImageView;
import android.widget.Toast;
public class MainActivity extends Activity implements OnClickListener{
public static final String TAG = "OpenCv_compare";
private Bitmap mBitmap1,mBitmap2;
private ImageView mIv_ImageView1,mIv_ImageView2;
private Button mBtn_compare;
private BaseLoaderCallback callback = new BaseLoaderCallback(this) {
@Override
public void onManagerConnected(int status) {
super.onManagerConnected(status);
switch (status) {
case BaseLoaderCallback.SUCCESS:
break;
default:
break;
}
}
};
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
init();
}
public void init(){
mBitmap1 = BitmapFactory.decodeResource(getResources(), R.drawable.b);
mBitmap2 = BitmapFactory.decodeResource(getResources(), R.drawable.c);
mIv_ImageView1 = (ImageView)findViewById(R.id.iv_img1);
mIv_ImageView2 = (ImageView)findViewById(R.id.iv_img2);
mBtn_compare = (Button)findViewById(R.id.btn_compare);
mIv_ImageView1.setImageBitmap(mBitmap1);
mIv_ImageView2.setImageBitmap(mBitmap2);
mBtn_compare.setOnClickListener(this);
}
@Override
public void onClick(View v) {
Mat mat1 = new Mat();
Mat mat2 = new Mat();
Mat mat11 = new Mat();
Mat mat22 = new Mat();
Utils.bitmapToMat(mBitmap1, mat1);
Utils.bitmapToMat(mBitmap2, mat2);
Imgproc.cvtColor(mat1, mat11, Imgproc.COLOR_BGR2GRAY);
Imgproc.cvtColor(mat2, mat22, Imgproc.COLOR_BGR2GRAY);
comPareHist(mat11, mat22);
}
private Mat mMat0;
private MatOfInt mChannels[];
private MatOfInt mHistSize;
private int mHistSizeNum = 25;
private MatOfFloat mRanges;
private Scalar mColorsRGB[];
private Point mP1;
private Point mP2;
private float mBuff[];
public Mat procSrc2GrayJni(Mat srcMat,int type) {
Mat grayMat = new Mat();
Imgproc.cvtColor(srcMat, grayMat, type);//轉換為灰階圖
// Imgproc.HoughCircles(rgbMat, gray,Imgproc.CV_HOUGH_GRADIENT, 1, 18);
// //霍夫變換找園
mChannels = new MatOfInt[] { new MatOfInt(0), new MatOfInt(1), new MatOfInt(2) };
mBuff = new float[mHistSizeNum];
mHistSize = new MatOfInt(mHistSizeNum);
mRanges = new MatOfFloat(0f, 256f);
mMat0 = new Mat();
mColorsRGB = new Scalar[] { new Scalar(200, 0, 0, 255), new Scalar(0, 200, 0, 255), new Scalar(0, 0, 200, 255) };
mP1 = new Point();
mP2 = new Point();
Mat rgba = srcMat;
Size sizeRgba = rgba.size();
Mat hist = new Mat(); //轉換直方圖進行繪制
int thikness = (int) (sizeRgba.width / (mHistSizeNum + 10) / 5);
if(thikness > 5) thikness = 5;
int offset = (int) ((sizeRgba.width - (5*mHistSizeNum + 4*10)*thikness)/2);
// RGB
for(int c=0; c<3; c++) {
Imgproc.calcHist(Arrays.asList(rgba), mChannels[c], mMat0, hist, mHistSize, mRanges);
Core.normalize(hist, hist, sizeRgba.height/2, 0, Core.NORM_INF);
hist.get(0, 0, mBuff);
for(int h=0; h<mHistSizeNum; h++) {
mP1.x = mP2.x = offset + (c * (mHistSizeNum + 10) + h) * thikness;
mP1.y = sizeRgba.height-1;
mP2.y = mP1.y - 2 - (int)mBuff[h];
Core.line(rgba, mP1, mP2, mColorsRGB[c], thikness);
}
}
return rgba;
}
/**
* 比較來個矩陣的相似度
* @param srcMat
* @param desMat
*/
public void comPareHist(Mat srcMat,Mat desMat){
srcMat.convertTo(srcMat, CvType.CV_32F);
desMat.convertTo(desMat, CvType.CV_32F);
double target = Imgproc.compareHist(srcMat, desMat, Imgproc.CV_COMP_CORREL);
Log.e(TAG, "相似度 : ==" + target);
Toast.makeText(this, "相似度 : ==" + target, 1000).show();
}
@Override
protected void onResume() {
super.onResume();
// 通過OpenCV引擎服務加載并初始化OpenCV類庫,所謂OpenCV引擎服務即是
// OpenCV_2.4.9.2_Manager_2.4_*.apk程式包,存在于OpenCV安裝包的apk目錄中
OpenCVLoader.initAsync(OpenCVLoader.OPENCV_VERSION_2_4_9, this,
callback);
}
}