I have written the following Code Sample that is supposed to create a peculiar-looking gradient and save it to a file specified by the user:
#include <stdio.h>
#include <cv.h>
#include <highgui.h>
static IplImage *image = 0;
void main() {
char path[1024];
int x, y;
CvScalar scalar;
scanf("%s", path);
image = cvCreateImage(cvSize(640,480),IPL_DEPTH_8U,1);
for (y = 0; y < 480; y++) {
for (x = 0; x < 640; x++) {
scalar = cvGet2D(image, x, y);
scalar.val[0]=(unsigned char)(x + y);
cvSet2D(image, x, y, scalar);
}
}
cvSaveImage(path, image, 0);
}
I compile it using: gcc opencv.c -o opencv `pkg-config --libs --cflags opencv` -lm and everything seems to be OK. However, during runtime (input: “sample.png”), I get the following error:
OpenCV Error: One of arguments' values is out of range (index is out of range) in cvPtr2D, file /builddir/build/BUILD/OpenCV-2.3.1/modules/core/src/array.cpp, line 1797 terminate called after throwing an instance of 'cv::Exception' what(): /builddir/build/BUILD/OpenCV-2.3.1/modules/core/src/array.cpp:1797: error: (-211) index is out of range in function cvPtr2D Aborted (core dumped)
Any help, please? Thanks in Advance! 🙂
cvGet2D and cvSet2D uses [row,column] convention like many other functions in opencv.
For further readings:
http://www.cs.iit.edu/~agam/cs512/lect-notes/opencv-intro/