OpenCv; Small Code using Erode and Dilate

Small Code that reads pbm image, convert it into 1 channel image. Erodes it, dilates it and shows them

#include <float.h>

#include <limits.h>

#include <time.h>

#include <ctype.h>

#include <iostream>

#include "BlobResult.h"

#include "blob.h"

#ifdef _EiC

#define WIN32

#endif

using namespace std;

void main(void){

IplImage *inputImage = cvLoadImage( "0584.pbm", 1 );

IplImage *gray = cvCreateImage( cvSize(inputImage->width,inputImage->height), 8, 1 );

cvCvtColor( inputImage, gray, CV_BGR2GRAY );

IplImage*img = inputImage;

inputImage = gray;

::cvReleaseImage(&img);

cvNamedWindow( "orig", 1 );

cvShowImage( "orig", inputImage );

IplImage *outputImage;

IplImage *outputImage2;

outputImage = cvCreateImage( cvSize( inputImage->width, inputImage->height ), IPL_DEPTH_8U, 1 );

outputImage2 = cvCreateImage( cvSize( inputImage->width, inputImage->height ), IPL_DEPTH_8U, 1 );

cvErode(inputImage, outputImage, 0, 1);

cvNamedWindow( "erode", 1 );

cvShowImage( "erode", outputImage );

 

cvDilate(outputImage, outputImage2, 0, 2);

cvNamedWindow( "dilate", 1 );

cvShowImage( "dilate", outputImage2 );

cvReleaseImage(&outputImage);

cvReleaseImage(&outputImage2);

cvWaitKey();

 

return;

}>

Writing PPM image file in C++

Following is the C++ code for writting the ppm image file

strtemp has file name,

fData is the pointer to the image data.

sprintf(strtemp,”%04d.ppm”,imageNo);
ofstream output(strtemp, ios::binary|ios::out);
if(!output){
cout << ” unable to open the output file “<< strtemp << endl;
}
else{
output << “P6″<< endl <<”# foreground “<<endl;
output << itoa(IWidth, strtemp, 10);
output << ” “;
output << itoa(IHeight, strtemp, 10);
output << endl;
output << itoa(255, strtemp, 10) << endl;
output.write( (char *)fData, IHeight*IWidth*3);
output.close();

};//end of else

OpenCv IplImage how to clear or initialize the image to scalar

just use the cvSet

e.g if img is the IplImage object pointer with 3 channels.

cvSet(img, cvScalar(0,0,0));

will set each and every pixel to zero.

Becarefull with the  channels and cvScalar used.