Jack Chung's profile - activity

Well I have to use Windows Application because I want to do a GUI, that will choose what image I will load with OpenCV. Then I will need to use WinMain right?

Could you explain those parameters, please? I didn't understand them.

Hello Guys,

I was using the OpenCV in Console Application and it was working fine, now I have to use Windows Application because I am doing a GUI to work with OpenCV.

How can I do OpenCV work in a Windows Application or How can I do GUI program in a Console Application?

I would appreciate it if someone could help me to solve that.

Thank you

How can I change the application type to SUBSYSTEM:CONSOLE? I am using Visual Studio.

Thanks for the fast answer

Hello Guys,

I was using the OpenCV in Console Application and it was working fine, now I have to use Windows Application because I am doing a GUI to work with OpenCV, but it is showing an error.

Please guys it is urgent, I would appreciate it if someone could help me to solve that.

Thank you

Hello guys,

I would like to know how to do an user interface. It is simple, I would like to create a window that I can choose what Image I want to load in my cvLoadImage, with buttons "OK" And "Cancel" to confirm or not the image to load.

OpenCV has functions to do that or should I do with language C? Can someone give me an example please?

I would apreciate it if someone could help me to do that.

Thank you.

The reason to use the old C is because I don't know how to use c++. Well, I tried to use what you said but it still not working, it is showing weird numbers in the console instead of 0 and 1 from the binary image.

Hello,

How can I write a value in a matrice?

I already created a matrice, read a binary image and get the pixel value, now I would like to write the pixel value in the matrice.

I would appreciate it if someone could help me to set the pixel value in the matrice.

The code that I read a binary image and try to write the pixel value in the matrice is:

#include <opencv\cv.h>
#include <opencv\highgui.h>
#include <stdio.h>
#include <stdlib.h>

int main()
{
    uchar binario, valor;

    if(fp == NULL){
        printf("\nNão encontrei arquivo\n");
        exit(EXIT_FAILURE);
    }

    CvMat* polar = cvCreateMat(20, 172, CV_8UC1);

    cvNamedWindow( "original", CV_WINDOW_AUTOSIZE );
    cvNamedWindow( "new", CV_WINDOW_AUTOSIZE );

    IplImage* src = cvLoadImage("Koala.jpg", CV_LOAD_IMAGE_GRAYSCALE);
    cvShowImage("original", src);

    CvSize size = cvSize(40, 40); 
    IplImage* resize = cvCreateImage(size, src->depth, src->nChannels); 

    cvResize(src, resize, CV_INTER_LINEAR);

    IplImage* img_binario = cvCreateImage(cvGetSize(resize), IPL_DEPTH_8U, 1);
    cvThreshold(resize, img_binario, 100, 255, CV_THRESH_BINARY);

    for(int i = 0; i < 20; i++){
//*((uchar*)CV_MAT_ELEM_PTR(*polar, i, 1)) = ((uchar *)(img_binario->imageData + i*img_binario->widthStep))[20];

      cvSet2D(polar, i, 1, ((uchar *)(img_binario->imageData + i*img_binario->widthStep))[20]);
    }

    printf("Valor: %i", polar);

    cvShowImage("new", img_binario);

    cvWaitKey(0);
    return 0;
}

Thank you.

Hello guys,

I am doing a project where I get the pixel value from a binary image (black and white - 0 and 255). Now I need to get this pixel value and send it with serial port, where a xBee is connected, but I don't know how can I do that.

I would appreciate it if someone could help me to send the pixel value to the xBee with serial port.

My code to get the pixel value from a binary image is:

#include <opencv\cv.h>
#include <opencv\highgui.h>
#include <stdio.h>
#include <stdlib.h>

int main()
{
    uchar binario, valor;

    FILE *fp;
    fp = fopen("Pixel.txt", "w");

    if(fp == NULL){
        printf("\nNão encontrei arquivo\n");
        exit(EXIT_FAILURE);
    }

    cvNamedWindow( "original", CV_WINDOW_AUTOSIZE );
    cvNamedWindow( "new", CV_WINDOW_AUTOSIZE );

    IplImage* src = cvLoadImage("Koala.jpg", CV_LOAD_IMAGE_GRAYSCALE);
    cvShowImage("original", src);

    CvSize size = cvSize(100, 100); 
    IplImage* resize = cvCreateImage(size, src->depth, src->nChannels); 

    cvResize(src, resize, CV_INTER_LINEAR);

    IplImage* img_binario = cvCreateImage(cvGetSize(resize), IPL_DEPTH_8U, 1);
    cvThreshold(resize, img_binario, 100, 255, CV_THRESH_BINARY);

    for(int i = 0; i < img_binario->height; i++){
        for(int j = 0; j < img_binario->width; j++){
            binario = ((uchar *)(img_binario->imageData + i*img_binario->widthStep))[j];

            if(binario == 255)
                valor = 1;
            else
                valor = 0;
            fprintf(fp, "Valor = %i\n", valor);
        }
    }

    fclose(fp);

    cvShowImage("new", img_binario);

    cvWaitKey(0);
    return 0;
}

Thank you.

Thank you very much, I made the mistake closing the fp inside the loop, that's why it was not working.

When I removed it, the code worked perfectly and gave to me the pixels from the video.

No it does not work....I dont know why, it just give pixel value (0, 0, 0) and just one time, I need to the whole video.

Hello guys,

I would like to get the pixel value from a video file, I already got the pixel value from an image and now I need to get from a video.

The code that I have doesn't work, it show in the text file only the pixel B=0, G=0, R=0 and just one image (400 line - 20 x 20 size), I need the pixel value from the whole video. I would appreciate it if someone could help me with that issue.

Here is my code for load a video, resize it and try to get the pixel value from resized video:

#include <opencv\cv.h>
#include <opencv\highgui.h>
#include <stdio.h>
#include <stdlib.h>

int main( int argc) {
    CvCapture* capture =  cvCreateFileCapture( "POV_112LEDs.avi" );
    IplImage* frame;

    uchar b, g, r;

    FILE *fp;
    fp = fopen("Matriz.txt", "w");

    if(fp == NULL){
        printf("\nNão encontrei arquivo\n");
        exit(EXIT_FAILURE);
    }

    char c;
    cvNamedWindow( "original", CV_WINDOW_AUTOSIZE );
    cvNamedWindow( "nova", CV_WINDOW_AUTOSIZE );

    while(1) {
        frame = cvQueryFrame( capture ); 

        if( !frame ) break;
        cvShowImage( "original", frame );

        CvSize size = cvSize(20, 20);
        IplImage* tmpsize = cvCreateImage(size, frame->depth, frame->nChannels);
        cvResize(frame, tmpsize, CV_INTER_LINEAR);

        for(int i = 0; i < tmpsize->height; i++){
            for(int j = 0; j < tmpsize->width; j++){
                b = ((uchar *)(tmpsize->imageData + i*tmpsize->widthStep))[j*tmpsize->nChannels + 0]; // b
                g = ((uchar *)(tmpsize->imageData + i*tmpsize->widthStep))[j*tmpsize->nChannels + 1]; // g
                r = ((uchar *)(tmpsize->imageData + i*tmpsize->widthStep))[j*tmpsize->nChannels + 2]; // r

                fprintf(fp, "B=%i, G=%i, R=%i\n", b, g, r);
            }
        }

        fprintf(fp, "------NEXT FRAME------");
        fclose(fp);

        cvShowImage("nova", tmpsize);

        c = cvWaitKey(33);
        if( c == 27 ) break;
    }

    cvReleaseCapture( &capture );
    cvDestroyWindow( "original" );
    cvDestroyWindow( "nova" );
}

Thanks, Regards, Jack.

Well, I am using the C interface because I don't know how to use the C++ interface. I will try to use that macro.

Thanks, Jack.

Hi guys,

I intend to get the pixel value from a picture, but I don't know how to do that, can someone help me please?

I have already loaded and resized an image, now I would like to get the pixel value from the new image and print it, probably I will need to use Matrices, but I don't know how. I would like to get the RGB pixel value and differentiate it in a matrix for each color ( Red, Green and Blue).

I would appreciate it if someone could help me with a sample code.

My code to load and resize the image is that:

#include <opencv\cv.h>
#include <opencv\highgui.h>

int main()
{
    cvNamedWindow( "original", CV_WINDOW_AUTOSIZE );
    cvNamedWindow( "new", CV_WINDOW_AUTOSIZE );

    IplImage* img = cvLoadImage("Koala.jpg");
    cvShowImage("original:",img);

    CvSize size = cvSize(800, 600); 
    IplImage* tmpsize=cvCreateImage(size, img->depth, img->nChannels); 

    cvResize(img,tmpsize,CV_INTER_LINEAR);
    cvShowImage("new",tmpsize);

    cvWaitKey(0);
    return 0;
}

Thank you, Jack.

I intend to do a project in my university, and the project is a POV Display: http://www.youtube.com/watch?v=QAGnpKz7zvY

I will do with a 32 LED RGB, and to send any image/video i will need to decrease the image, but decreasing it, probably it will get a bad quality to see and understand something, tha's why I need to interpolate too, so I think it need to decrease the size and interpolate to get some quality.

It's difficult to explain it, did you understand something that I said?

Hello,

How can I decrease one image/video and interpolate it?

There is any library?

Thanks, Regards.

Hello,

I would appreciate it if someone could inform me if I can process images with OpenCV.

I want to give 1 video as archive and I need to decrease the screen, but it probably will get bad pixels and without focus, then I need to interpolate/polarize the image, can I do that with OpenCV?

Thank you. Regards, Jack.