This code is supposed to blur an image together with other supporting files as per CS50 Pset4. I am able to compile my code with no errors and run the program but it does not seem to blur my image correctly, i get a very very dark contrast image as output.

Does anyone see anything wrong with my code? New to coding so please help!! thank youu

// Blur image
void blur(int height, int width, RGBTRIPLE image[height][width])
{
RGBTRIPLE tmpimg[height][width];
RGBTRIPLE sum;
for(int i = 0; i < height; i++)
{
    for(int j = 0; j < width; j++)
    {
        int counter = 0;
        sum.rgbtRed = 0;
        sum.rgbtGreen = 0;
        sum.rgbtBlue = 0;
        for(int a = -1; a < 2; a++)
        {
            for (int b = -1; b < 2; b++)
            {
                if((i + a) > 0 || (i + a) < height - 1 || (j + b) > 0 || (j + b) < width - 1)
                {
                    sum.rgbtRed += image[i + a][j + b].rgbtRed;
                    sum.rgbtGreen += image[i + a][j + b].rgbtGreen;
                    sum.rgbtBlue += image[i + a][j + b].rgbtBlue;
                    counter++;
                }
            }
        }
        tmpimg[i][j].rgbtRed = round(sum.rgbtRed / counter);
        tmpimg[i][j].rgbtGreen = round(sum.rgbtGreen / counter);
        tmpimg[i][j].rgbtBlue = round(sum.rgbtBlue / counter);
    }
}
for(int i = 0; i < height; i++)
{
    for(int j = 0; j < width; j++)
    {
        image[i][j] = tmpimg[i][j];
    }
}
return;

}