Turn an image by 90 degree

Turn an image by 90 degree

// C program to turn an

// image by 90 Degree

#include <stdio.h>

#include <stdlib.h>

void displayMatrix(unsigned int const *p,

                   unsigned int row,

                   unsigned int col);

void rotate(unsigned int *pS,

            unsigned int *pD,

            unsigned int row,

            unsigned int col);            

void displayMatrix(unsigned int const *p,

                   unsigned int r,

                   unsigned int c)

{

    unsigned int row, col;

    printf("\n\n");

    for (row = 0; row < r; row++)

    {

        for (col = 0; col < c; col++)

            printf("%d\t", * (p + row * c + col));

        printf("\n");

    }

    printf("\n\n");

}

void rotate(unsigned int *pS,

            unsigned int *pD,

            unsigned int row,

            unsigned int col)

{

    unsigned int r, c;

    for (r = 0; r < row; r++)

    {

        for (c = 0; c < col; c++)

        {

            *(pD + c * row + (row - r - 1)) =

                            *(pS + r * col + c);

        }

    }

}

// Driver Code

int main()

{

    // declarations

    unsigned int image[][4] = {{1,2,3,4},

                               {5,6,7,8},

                               {9,10,11,12}};

    unsigned int *pSource;

    unsigned int *pDestination;

    unsigned int m, n;

    // setting initial values

    // and memory allocation

    m = 3, n = 4, pSource = (unsigned int *)image;

    pDestination =

        (unsigned int *)malloc

        (sizeof(int) * m * n);

   // process each buffer

    displayMatrix(pSource, m, n);

    rotate(pSource, pDestination, m, n);

    displayMatrix(pDestination, n, m);

    free(pDestination);

    getchar();

    return 0;

}

Output :

1    2    3    4   

5    6    7    8   

9    10    11    12  

9    5    1   

10    6    2   

11    7    3   

12    8    4