To those who struggle with pset4’s filter-more’s edge detection filter

Question

I’m sure it is obvious for some people, but it wasn’t for me)

If your code isn’t working the way it should, you can create new .c file and put there your logic from edge detection function.

You can hardcode input from one of the test cases which your code isn’t passing and simplify task by finding Gx, Gy and new color value only for one color channel.

After that, using debug50 you go through your code step-by-step watching closely changing values of your variables)

debug50 is amazingly useful and powerful tool)

happy coding!

Answer 1

Well, good idea. I did this and actually figured out, that my program is perfectly working in a dedicated file with hardcode:

{rgbtBlue = 210, rgbtGreen = 150, rgbtRed = 60}

When I run the check50, it is doing wrong.

Hardcode:

int height = 3;
int width = 3;
RGBTRIPLE image[height][width];

image[0][0].rgbtRed = 25;
image[0][0].rgbtGreen = 10;
image[0][0].rgbtBlue = 0;

image[0][1].rgbtRed = 30;
image[0][1].rgbtGreen = 10;
image[0][1].rgbtBlue = 0;

image[0][2].rgbtRed = 80;
image[0][2].rgbtGreen = 60;
image[0][2].rgbtBlue = 40;

image[1][0].rgbtRed = 90;
image[1][0].rgbtGreen = 30;
image[1][0].rgbtBlue = 20;

image[1][1].rgbtRed = 100;
image[1][1].rgbtGreen = 40;
image[1][1].rgbtBlue = 30;

image[1][2].rgbtRed = 90;
image[1][2].rgbtGreen = 70;
image[1][2].rgbtBlue = 80;

image[2][0].rgbtRed = 40;
image[2][0].rgbtGreen = 20;
image[2][0].rgbtBlue = 20;

image[2][1].rgbtRed = 30;
image[2][1].rgbtGreen = 10;
image[2][1].rgbtBlue = 30;

image[2][2].rgbtRed = 10;
image[2][2].rgbtGreen = 40;
image[2][2].rgbtBlue = 50;

Any idea?

Debug50 result after middle pixel:

{{{rgbtBlue = 76, rgbtGreen = 117, rgbtRed = 255}, {rgbtBlue = 213, rgbtGreen = 228, rgbtRed = 255}, {rgbtBlue = 192, rgbtGreen = 190, rgbtRed = 255}}, {{rgbtBlue = 114, rgbtGreen = 102, rgbtRed = 255}, {rgbtBlue = 210, rgbtGreen = 150, rgbtRed = 60}, {rgbtBlue = 0, rgbtGreen = 0, rgbtRed = 0}}, {{rgbtBlue = 0, rgbtGreen = 0, rgbtRed = 0}, {rgbtBlue = 0, rgbtGreen = 0, rgbtRed = 0}, {rgbtBlue = 0, rgbtGreen = 0, rgbtRed = 0}}}