CS50 pset 4 // 棕褐色滤镜

Question

Hello I am having an issue with the sepia filter for my cs50 course this is the error it gives me.I am really not sure what the issue is. If anyone could help me that would be great

void sepia(int height, int width, RGBTRIPLE image[height][width])
{
double sepiaRed;
double sepiaGreen;
double sepiaBlue;

for (int i = 0; i < height; i++)
{
    for (int j = 0; j < width; j++)
    {
        sepiaRed = (0.393 * image[i][j].rgbtRed) + (0.769 * image[i][j].rgbtGreen) + (0.189 * image[i][j].rgbtBlue);
        sepiaGreen = (0.349 * image[i][j].rgbtRed) + (0.686 * image[i][j].rgbtGreen) + (0.168 * image[i][j].rgbtBlue);
        sepiaBlue = (0.272 * image[i][j].rgbtRed) + (0.534 * image[i][j].rgbtGreen) + (0.131 * image[i][j].rgbtBlue);


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

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

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

        else{
            image[i][j].rgbtRed = round(sepiaRed);
            image[i][j].rgbtGreen = round(sepiaGreen);
            image[i][j].rgbtBlue = round(sepiaBlue);
        }

     }
}
return;

}

Answer 1

In the cases where you clamp one component to 255 you have not updated the other components. I suggest changing the faulty logic in this section of the code

if( sepiaRed > 255) {
    image[i][j].rgbtRed = 255;
}
else if(sepiaGreen > 255) {
    image[i][j].rgbtGreen = 255;
}
else if(sepiaBlue > 255) {
    image[i][j].rgbtBlue = 255;
}
else {
    image[i][j].rgbtRed = round(sepiaRed);
    image[i][j].rgbtGreen = round(sepiaGreen);
    image[i][j].rgbtBlue = round(sepiaBlue);
}

to this, which clamps each component and then writes them all

if(sepiaRed > 255) {
    sepiaRed = 255;
}
if(sepiaGreen > 255) {
    sepiaGreen = 255;
}
if(sepiaBlue > 255) {
    sepiaBlue = 255;
}
image[i][j].rgbtRed = round(sepiaRed);
image[i][j].rgbtGreen = round(sepiaGreen);
image[i][j].rgbtBlue = round(sepiaBlue);