CS50 pset4 的棕褐色滤镜

Question

So I've tried writing code for sepia filter, but its not working properly for corner cases. I dont find any issue. But error is being prompted.

The below image is the picture of my errors

I tried running the program in VS code, it gives desired output. But check50 prompts error message.

void sepia(int height, int width, RGBTRIPLE image[height][width])
{
    for(int i = 0; i < height; i++)
    {
        for (int j = 0; j < width; j++)
        {
            float r = image[i][j].rgbtRed;
            float g = image[i][j].rgbtGreen;
            float b = image[i][j].rgbtBlue;

            image[i][j].rgbtRed = round(0.393*r + 0.769*g + 0.189*b);
            image[i][j].rgbtGreen = round(0.349*r + 0.686*g + 0.168*b);
            image[i][j].rgbtBlue = round(0.272*r + 0.534*g + 0.131*b);

            if (image[i][j].rgbtRed > 255)
            {
                image[i][j].rgbtRed = 255;
            }

            if (image[i][j].rgbtGreen > 255)
            {
                image[i][j].rgbtGreen = 255;
            }

            if (image[i][j].rgbtBlue > 255)
            {
                image[i][j].rgbtBlue = 255;
            }

        }
    }
    return;
}

Answer 1

Your sepia function is almost correct. You just missed that with

            image[i][j].rgbtRed = round(0.393*r + 0.769*g + 0.189*b);
            image[i][j].rgbtGreen = round(0.349*r + 0.686*g + 0.168*b);
            image[i][j].rgbtBlue = round(0.272*r + 0.534*g + 0.131*b);

the members rgbtRed , rgbtGreen and rgbtBlue are only 8 bits and the behavior of assigning floating type values from 256 on to them is undefined; the following code to cap the values can't work. So cap the RGB values before assigning them:

            image[i][j].rgbtRed   = fmin(round(0.393*r + 0.769*g + 0.189*b), 255);
            image[i][j].rgbtGreen = fmin(round(0.349*r + 0.686*g + 0.168*b), 255);
            image[i][j].rgbtBlue  = fmin(round(0.272*r + 0.534*g + 0.131*b), 255);