Allocating memory for arrays

[xHolyWrath]

Hi everyone! I'm new to this forum so any advise will be very much appreciated.

I'm currently creating a C program that would read a text file full of integer values that represents pixel spectrum values of an image(satellite image) and do some computation on it so I can classify them into dry grass, road, trees, water, building,etc.

The text files contains 4 values for each pixel representing 4 bands(band 1,band 2 band 3, band 4) for each pixel so if i have a 4x5 image i would have a total of 16 rows and 5 columns. the first 4 rows would be for band 1 representation of the image,the next 4 rows would be for band 2 representation of the image...

Im using 2D arrays in storing these pixel values from the file,it works for that 4x5 image but when i use a file representing a 400x400 image it crashes. So i think it has a problem in allocating memory for my arrays.

here's a copy of the code i created.

#include <stdio.h>
#include <stdlib.h>
#include <math.h>

void stripNewline(char *string,int size);

int main()
{
    char fileName[30];
    int rows, cols, bands;

    //user input
    printf("================ TEST IMAGE ===============\n");
    printf("Enter the SBQ text file: ");
    fgets(fileName,30,stdin);
    stripNewline(fileName,30);
    printf("Enter the number of rows in the test image: ");
    scanf("%d",&rows);
    printf("Enter the number of columns in the test image: ");
    scanf("%d",&cols);
    printf("Enter the number of bands used in the test image: ");
    scanf("%d",&bands);

    printf("\n================ REFERENCE SPECTRA ===============\n");
    //prepare matrix for reference
    int referenceArray[bands],b,i;
    i = 1;
    for(b=0;b<bands;b++){
        printf("Spectrum value for Band %d: ",i);
        scanf("%d",&referenceArray[b]);
        i++;
    }

    //get data from file
    FILE *file;
    static int imageArray[20][4];
    int p;

    printf("\nOPENING FILE...\n");
    file = fopen(fileName,"r");

    if(file == 0){
        printf("%s could not be opened\n",fileName); //file not found or does not exist
    }else{
        printf("%s OPENED SUCCESSFULLY\n",fileName); //opened file

        printf("\nPREPARING NEEDED MATRICES FOR CLASSIFICATION...\n");

        //prepare matrices of each test pixel in image
        for(b=(bands-1);b>=0;b--){
            for(p=0;p<(rows*cols);p++){
                fscanf(file,"%d",&imageArray[p][b]);
            }
        }

        printf("\nCLASSIFYING USING SAM...\n");

        //COMPUTE FOR COSINE OF ANGLE
        //compute for numerator
        int summationOfTR[(rows*cols)];
        for(p=0;p<(rows*cols);p++){
            summationOfTR[p] = '\0';
            for(b=0;b<bands;b++){
                summationOfTR[p] = summationOfTR[p] + (imageArray[p][b] * referenceArray[b]);
            }
            //printf("%d\n", summationOfTR[p]);
        }
        //compute for denominator
        int summationOfT2[(rows*cols)];
        double sqrtSumOfT2[(rows*cols)];
        int summationOfR2 = 0;
        double sqrtSumOfR2 = 0;
        double denominator[(rows*cols)];
        //summationOfT2
        for(p=0;p<(rows*cols);p++){
            summationOfT2[p] = '\0';
            for(b=0;b<bands;b++){
                summationOfT2[p] = summationOfT2[p] + pow(imageArray[p][b],2);
            }
            //printf("%d\n", summationOfT2[p]);
        }
        //sqrtSumOft2
        for(p=0;p<(rows*cols);p++){
            sqrtSumOfT2[p] = '\0';
            sqrtSumOfT2[p] = sqrt(summationOfT2[p]);
        }

        //summationofR2
        for(b=0;b<bands;b++){
            summationOfR2 = summationOfR2 + pow(referenceArray[b],2);
        }
        //sqrtSumOfR2
        sqrtSumOfR2 = sqrt(summationOfR2);
        //denominator
        for(p=0;p<(rows*cols);p++){
            denominator[p] = '\0';
            denominator[p] = sqrtSumOfT2[p] * sqrtSumOfR2;
        }

        //cosine of angle
        double cosineOfAngles[(rows*cols)];
        for(p=0;p<(rows*cols);p++){
            cosineOfAngles[p] = '\0';
            cosineOfAngles[p] = summationOfTR[p] / denominator[p];

            if((p%(cols)) == 0){
                printf("\n");
            }
            printf("%.5lf ",cosineOfAngles[p]);
        }


        fclose(file);
    }

    getchar();
    return 0;
}


//strip newline character '\n' after getting string input from user
void stripNewline(char *string,int size){
    int i;
    for(i=0;i<size;i++){
        if(string[i] == '\n'){
            string[i] = '\0';
            break;
        }
    }
}

Thanks in advance!

[Banfa]

Line 36, you allocate a fixed amount of memory instead of the amount the user requested.