问题
I am using opencv 2.4.8 and studio 2013, n i am getting a run time error.my main code is this..
#include<opencv2\core\core.hpp>
#include<opencv2\highgui\highgui.hpp>
#include<opencv2\imgproc\imgproc.hpp>
#include"SIFT.h"
#include<iostream>
#include<stdio.h>
#include<conio.h>
using namespace cv;
using namespace std;
int main()
{
cout << "hello";
Mat image = imread("abc.jpg",0);
cout << image.channels() << endl;
SIFT controller(image);
controller.DoSIFT();
waitKey(100000);
}
and my header file code is as below
#include<opencv2\core\core.hpp>
#include<opencv2\highgui\highgui.hpp>
#include<opencv2\imgproc\imgproc.hpp>
#include<iostream>
using namespace cv;
using namespace std;
class SIFT{
private:
Mat image_orig;
Mat Scale_spaces[4][6];
Mat LOG_img[4][4];
Mat Extrema[4][2];
Mat image_temp;
Mat middle, up, down;
void BuildScaleSpace()
{
cout << "in build space" <<endl;
int i, j;
//image should be in grey scale
cout << endl<<image_temp.rows << image_temp.cols << endl;
GaussianBlur(image_temp, image_temp, cv::Size(5, 5), 0.5);
resize(image_temp, image_temp, Size(image_temp.cols * 2, image_temp.rows * 2), 0, 0, 1);
cout << image_temp.rows << image_temp.cols << endl;
Scale_spaces[0][0] =image_temp;
cout << endl << image_temp.rows << image_temp.cols << endl;
GaussianBlur(Scale_spaces[0][0], Scale_spaces[0][0], cv::Size(5, 5), 1);
double int_sigma = sqrt(2) / 2;
double sigma = int_sigma;;
double mid;
double power = 1.0;
for (i = 0; i < 4; i++)
{
if (i>0)
{
sigma = mid;
Scale_spaces[i][0] = image_temp;
resize(image_temp, Scale_spaces[i][0], Size(image_temp.cols / power, image_temp.rows / power), 0, 0, 1);
cout << endl << "after resizing" << Scale_spaces[i][0].rows << Scale_spaces[i][0].cols << endl;
}
for (j = 1; j <= 5; j++)
{
if (j == 2)
mid = sigma;
// printf(" %f ", sigma);
GaussianBlur(Scale_spaces[i][j-1], Scale_spaces[i][j], cv::Size(5, 5), sigma);
sigma = sigma*sqrt(2);
}
// printf("\n");
power = power * 2;
}
}
void ShowScaleSpace()
{
cout << "\n show scale\n\n";
namedWindow("image", CV_WINDOW_AUTOSIZE);
int i, j;
for (i = 0; i < 4; i++)
{
for (j = 0; j <= 5; j++)
{
cout << i<<" "<<j<<endl;
cout << Scale_spaces[i][j].rows<<" " << Scale_spaces[i][j].cols << endl;
imshow("image", Scale_spaces[i][j]);
cvWaitKey(700);
}
}
}
void FindLOG()
{
cout << endl << "IN LOG " << endl;
int i;
int j;
for (i = 0; i < 4; i++)
{
for (j = 1; j < 5; j++)
{
addWeighted(Scale_spaces[i][j], 1, Scale_spaces[i][j + 1], -1,0, LOG_img[i][j - 1]);
}
}
}
void FindMaxMin()
{
cout << endl << "IN findmaxmin " << endl;
int i;
int j;
int xiter, yiter;
for (i = 0; i < 4; i++)
{
for (j = 1; j < 3; j++)
{
std::cout << LOG_img[i][j].channels();
middle = LOG_img[i][j].clone();
up = LOG_img[i][j - 1].clone();
down = LOG_img[i][j + 1].clone();
for (yiter = 1; yiter < middle.rows-1; yiter++)
{
for (xiter = 1; xiter < middle.cols-1; xiter++)
{
cout << i << " " << j << " " << yiter << " " << xiter<< " "<<endl;
double currentPixel = middle.at<uchar>(yiter, xiter);
cout << "1 ";
// Check for a maximum
if (cout << "helllo 2hhukjhgkj"&¤tPixel> middle.at<uchar>(yiter, xiter + 1) &&
currentPixel> middle.at<uchar>(yiter, xiter - 1) &&
currentPixel > middle.at<uchar>(yiter + 1, xiter) &&
currentPixel > middle.at<uchar>(yiter + 1, xiter - 1) &&
currentPixel > middle.at<uchar>(yiter, xiter + 1) &&
currentPixel > middle.at<uchar>(yiter - 1, xiter) &&
currentPixel > middle.at<uchar>(yiter - 1, xiter + 1) &&
currentPixel > middle.at<uchar>(yiter - 1, xiter - 1) &&
currentPixel > up.at<uchar>(yiter, xiter) &&
currentPixel > up.at<uchar>(yiter, xiter + 1) &&
currentPixel > up.at<uchar>(yiter, xiter - 1) &&
currentPixel > up.at<uchar>(yiter + 1, xiter) &&
currentPixel > up.at<uchar>(yiter + 1, xiter - 1) &&
currentPixel > up.at<uchar>(yiter, xiter + 1) &&
currentPixel > up.at<uchar>(yiter - 1, xiter) &&
currentPixel > up.at<uchar>(yiter - 1, xiter + 1) &&
currentPixel > up.at<uchar>(yiter - 1, xiter - 1) &&
currentPixel > down.at<uchar>(yiter, xiter) &&
currentPixel > down.at<uchar>(yiter, xiter + 1) &&
currentPixel > down.at<uchar>(yiter, xiter - 1) &&
currentPixel > down.at<uchar>(yiter + 1, xiter) &&
currentPixel > down.at<uchar>(yiter + 1, xiter - 1) &&
currentPixel > down.at<uchar>(yiter, xiter + 1) &&
currentPixel > down.at<uchar>(yiter - 1, xiter) &&
currentPixel > down.at<uchar>(yiter - 1, xiter + 1) &&
currentPixel > down.at<uchar>(yiter - 1, xiter - 1)
)
{
cout << "inside, updating extrema ";
Extrema[i][j - 1].at<uchar>(xiter, yiter) = 255;
}
else if (currentPixel< middle.at<uchar>(yiter, xiter + 1) &&
currentPixel< middle.at<uchar>(yiter, xiter - 1) &&
currentPixel < middle.at<uchar>(yiter + 1, xiter) &&
currentPixel < middle.at<uchar>(yiter + 1, xiter - 1) &&
currentPixel < middle.at<uchar>(yiter, xiter + 1) &&
currentPixel < middle.at<uchar>(yiter - 1, xiter) &&
currentPixel < middle.at<uchar>(yiter - 1, xiter + 1) &&
currentPixel < middle.at<uchar>(yiter - 1, xiter - 1) &&
currentPixel < up.at<uchar>(yiter, xiter) &&
currentPixel < up.at<uchar>(yiter, xiter + 1) &&
currentPixel < up.at<uchar>(yiter, xiter - 1) &&
currentPixel < up.at<uchar>(yiter + 1, xiter) &&
currentPixel < up.at<uchar>(yiter + 1, xiter - 1) &&
currentPixel < up.at<uchar>(yiter, xiter + 1) &&
currentPixel < up.at<uchar>(yiter - 1, xiter) &&
currentPixel < up.at<uchar>(yiter - 1, xiter + 1) &&
currentPixel < up.at<uchar>(yiter - 1, xiter - 1) &&
currentPixel < down.at<uchar>(yiter, xiter) &&
currentPixel < down.at<uchar>(yiter, xiter + 1) &&
currentPixel < down.at<uchar>(yiter, xiter - 1) &&
currentPixel < down.at<uchar>(yiter + 1, xiter) &&
currentPixel < down.at<uchar>(yiter + 1, xiter - 1) &&
currentPixel < down.at<uchar>(yiter, xiter + 1) &&
currentPixel < down.at<uchar>(yiter - 1, xiter) &&
currentPixel < down.at<uchar>(yiter - 1, xiter + 1) &&
currentPixel < down.at<uchar>(yiter - 1, xiter - 1)
)
{
Extrema[i][j - 1].at<uchar>(xiter, yiter) = 255;
}
else
Extrema[i][j - 1].at<uchar>(xiter, yiter) = 0;
}
}
}
}
}
public:
SIFT(Mat Image)
{
image_orig = Image;
image_temp = Image;
}
void DoSIFT()
{
BuildScaleSpace();
//ShowScaleSpace();
FindLOG();
FindMaxMin();
}
};
the build is successful but, at the run time it is showing the following error.
the error might be in the FindMaxMin() function and in this line
currentPixel> middle.at<uchar>(yiter, xiter + 1)
But I am not able to rectify it.
回答1:
Sorry, @user2396315, I didn't visit here constantly.
The problem is You didn't initial "Extrema", with Mat::create() with correct size and type. You only declared it "Mat Extrema[4][2];"
So after the if else...
Extrema[i][j - 1].at<uchar>(xiter, yiter) = ??? ;
will access an empty Mat "Extrema[i][j - 1]".
You may put
if( Extrema[i][j - 1].empty() == true )
cerr << "Fatal error" << endl ;
before it and you will see.
Always check your Mat by Mat::empty() before you use it. That is what I meant "Check the size" at this post. I didn't mean to check the size of arrays.
Remember, "Assertion failed" usually means you have passed an empty Mat or Mat with incorrect size as expectation.
回答2:
The if (cout << "message" && doesn't seem like very good practice. Separate the controls from the information output for a start.
Also, you're going to want to check and make sure your xiter and yiter variables are within the bounds you expect. Fixing this will very likely fix your issue.
来源：https://stackoverflow.com/questions/22587103/assertion-error-while-implementing-sift-algorithm-opencv