如何在OpenCV中从Mat对象m读取每个像素的值作为RGB值

时间:2012-12-28 16:42:52

标签: java android opencv

这是我从rectangle.jpg阅读图片/sdcard的代码。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?<​​/ p>

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");
        } 
    }

}

2 个答案:

答案 0 :(得分:9)

Mat.get(x, y) - 返回(x,y)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,那么您将得到一个[r,g,b]数组。

Mat.put(x, y, value) - 将(x,y)的频道值设置为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

答案 1 :(得分:0)

OpenCV中使用的函数是double[] Mat::get(int row, int col)