英文:
So, this function was supposed to use edge detection and apply sobel filter. But well It doesn't
问题
我试图弄清楚我做错了什么。我的意图在标题中 
这是我尝试的代码，显然它不起作用。它只打印一个纯色，边缘也尚未包括。我无法弄清楚这段代码的哪个部分是错误的。它只是一个用C编写的函数。
void edges(int height, int width, RGBTRIPLE image[height][width])
{
RGBTRIPLE edit[height][width];
for (int i = 0; i < height; i++)
{
for (int j = 0; j < width; j++)
{
edit[i][j] = image[i][j];
}
}
for (int q = 1; q < height - 1; q++)
{
for (int w = 1; w < width - 1; w++)
{
// 这里是对图像进行边缘检测的代码
// 你可以继续调试和改进这个函数
}
}
return;
}
请注意，这只是一个边缘检测函数的框架，其中还没有实际的边缘检测逻辑。你需要在相应的部分添加代码以完成边缘检测。
英文:
I'm trying to figure out what I did wrong. My intent is in title
This is the code I tried, and it clearly isn't working. It just print's 1 solid colour, also edges are not included yet. What part is wrong I can't figure it out what part of this code is wrong. It's just a function and it's in C.
void edges(int height, int width, RGBTRIPLE image[height][width])
{
RGBTRIPLE edit[height][width];
for (int i = 0; i < height; i++)
{
for (int j = 0; j < width; j++)
{
edit[i][j] = image[i][j];
}
}
for (int q = 1; q < height - 1; q++)
{
for (int w = 1; w < width - 1; w++)
{
int redEdit[9];
int greenEdit[9];
int blueEdit[9];
for (int top = 0; top < 3; top++)
{
redEdit[top] += edit[q - 1][w - 1 + top].rgbtRed;
greenEdit[top] += edit[q - 1][w - 1 + top].rgbtGreen;
blueEdit[top] += edit[q - 1][w - 1 + top].rgbtBlue;
}
int midctr = 0;
for (int mid = 3; mid < 6; mid++)
{
redEdit[mid] += edit[q][w - 1 + midctr].rgbtRed;
greenEdit[mid] += edit[q][w - 1 + midctr].rgbtGreen;
blueEdit[mid] += edit[q][w - 1 + midctr].rgbtBlue;
midctr ++;
}
int topctr = 0;
for (int top = 6; top < 9; top++)
{
redEdit[top] += edit[q + 1][w - 1 + topctr].rgbtRed;
greenEdit[top] += edit[q + 1][w - 1 + topctr].rgbtGreen;
blueEdit[top] += edit[q + 1][w - 1 + topctr].rgbtBlue;
topctr ++;
}
int matrixgx[] = {-1, 0, 1, -2, 0, 2, -1, 0, 1};
int matrixgy[] = {- 1, -2, -1, 0, 0, 0, 1, 2, 1};
int redEditgx[9];
int greenEditgx[9];
int blueEditgx[9];
int redEditgy[9];
int greenEditgy[9];
int blueEditgy[9];
for (int mtrx = 0; mtrx < 9; mtrx++)
{
redEditgx[mtrx] = redEdit[mtrx] * matrixgx[mtrx];
greenEditgx[mtrx] = greenEdit[mtrx] * matrixgx[mtrx];
blueEditgx[mtrx] = blueEdit[mtrx] * matrixgx[mtrx];
redEditgy[mtrx] = redEdit[mtrx] * matrixgy[mtrx];
greenEditgy[mtrx] = greenEdit[mtrx] * matrixgy[mtrx];
blueEditgy[mtrx] = blueEdit[mtrx] * matrixgy[mtrx];
}
// now sum up the changes of gx and gt
int redSumgx = 0;
int greenSumgx = 0;
int blueSumgx = 0;
int redSumgy = 0;
int greenSumgy = 0;
int blueSumgy = 0;
for (int sum = 0; sum < 9; sum++)
{
redSumgx += redEditgx[sum];
greenSumgx += greenEditgx[sum];
blueSumgx += blueEditgx[sum];
redSumgy += redEditgy[sum];
greenSumgy += greenEditgy[sum];
blueSumgy += blueEditgy[sum];
}
int finalRed = round(sqrt(pow(redSumgx, 2) + pow(redSumgy, 2)));
int finalGreen = round(sqrt(pow(greenSumgx, 2) + pow(greenSumgy, 2)));
int finalBlue = round(sqrt(pow(blueSumgx, 2) + pow(blueSumgy, 2)));
if (finalRed > 255)
{
finalRed = 255;
}
if (finalGreen > 255)
{
finalGreen = 255;
}
if (finalBlue > 255)
{
finalBlue = 255;
}
image[q][w].rgbtRed = finalRed;
image[q][w].rgbtGreen = finalGreen;
image[q][w].rgbtBlue = finalBlue;
}
}
return;
}
I know this code is cancer please don't judge
答案1
得分: 1
这些数组
int redEdit[9];
int greenEdit[9];
int blueEdit[9];
尚未初始化，包含任意值。因此，当您执行诸如
redEdit[top] += edit[q - 1][w - 1 + top].rgbtRed;
这样的语句时，求和是没有意义的。您需要
int redEdit[9] = { 0 };
int greenEdit[9] = { 0 };
int blueEdit[9] = { 0 };
只有静态变量会被隐式初始化为0。局部（自动）变量不会被初始化。
英文:
These arrays
int redEdit[9];
int greenEdit[9];
int blueEdit[9];
have not been initialised and hold arbitrary values. So when you execute statements such as
redEdit[top] += edit[q - 1][w - 1 + top].rgbtRed;
the sum is meaningless. You need
int redEdit[9] = { 0 };
int greenEdit[9] = { 0 };
int blueEdit[9] = { 0 };
Only static variables are implicitly initialised to 0. Local (auto) variables are not.
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