如何在OpenCV中从Mat对象m读取每个像素的值作为RGB值

Question

这是我rectangle.jpg从中读取图像的代码/sdcard.我想知道像素值(正常,以及RGB格式).我应该使用什么代码来处理它？

package com.idag.edge;

import android.os.Bundle;
import android.os.Environment;
import android.app.Activity;
import android.util.Log;
import android.widget.TextView;

import org.opencv.android.OpenCVLoader;
import org.opencv.core.Mat;
import org.opencv.highgui.Highgui;

public class MainActivity extends Activity {  
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        try
        {
            String path=Environment.getExternalStorageDirectory().getAbsolutePath() +"/rectangle.jpg";
            Mat m=Highgui.imread(path,1); 
            Log.i("Paramenres on matrix", "height "+ m.height()+" width "+ m.width()+" total = "+m.total()+" channels " +m.channels());

            System.out.println("element at 0 0 = "+ m.row(0).col(0).nativeObj+" element at 150 150 = "+ m.row(150).col(150).nativeObj);
        }

        catch(Exception e){
            System.err.print("Error in the code");
            Log.i("Error in imread", "Error in imread");
        } 
    }

}

Answer 1

Mat.get(x, y)- 返回(x,y)处所有通道值的数组,每个通道位于不同的位置.如果您的图像是RGB,那么您将获得[r,g,b]的数组.

Mat.put(x, y, value)- 将(x,y)处的通道值设置为value.

double[] rgb = image.get(0, 0);
Log.i("", "red:"+rgb[0]+"green:"+rgb[1]+"blue:"+rgb[2]);
image.put(0, 0, new double[]{255, 255, 0});//sets the pixel to yellow