Question

我已经多次发布这个程序，但是它有不同的麻烦。我想写一个算法来模糊图像，到目前为止，我已经将灰度图像的每个像素值都变成**char数组。从那里，我的计划是遍历每个像素，查看其直接相邻像素，将它们的值与我当前正在查看的像素相加，并获得所有这些像素的平均值。

完成后，我想将我正在查看的像素设置为该平均值。我为此编写了部分代码，我相信我正确地添加了它，但仍然没有得到结果图像。在将其分配给像素之前，我必须为我的总和提供演员表吗？

代码：

#include <stdio.h>
#include <stdlib.h>

int main()
{
    FILE *fin, *fout;
    char path_in[64], path_out[64];
    unsigned char **rev, px;
    int sum, width, height, read, row, i, j;

    printf("Input file name: ");
    scanf("%s", path_in);
    printf("Output file name: ");
    scanf("%s", path_out);

    printf("Width of image (in pixels): ");
    scanf("%d", &width);
    printf("Height of image (in pixels): ");
    scanf("%d", &height);

    fin = fopen(path_in, "rb");
    fout = fopen(path_out, "wb");

    rev = (unsigned char **)malloc(height * sizeof(unsigned char *));
    for(i = 0; i < height; i++)
        rev[i] = (unsigned char *)malloc(width * sizeof(unsigned char));

    for(i = 0; i < height; i++)
    {
        for(j = 0; j < width; j++)
        {
            read = fread(&px, sizeof(char), 1, fin);
            rev[i][j] = px;
        }
    }

    sum = 0;
    for(i = 0; i < height; i++)
    {
        for(j = 0; j < width; j++)
        {
            //Top row of image
            if(i == 0)
            {
                if(j == 0)
                    sum = ((unsigned)rev[i][j] + (unsigned)rev[i][j + 1] + 
                            (unsigned)rev[i + 1][j] + (unsigned)rev[i + 1][j + 1]) / 4;
                else if(j == width - 1)
                    sum = ((unsigned)rev[i][j] + (unsigned)rev[i][j - 1] +
                            (unsigned)rev[i + 1][j] + (unsigned)rev[i + 1][j - 1]) / 4;
                else
                    sum = ((unsigned)rev[i][j] + (unsigned)rev[i][j - 1] + (unsigned)rev[i][j + 1] +
                            (unsigned)rev [i + 1][j] + (unsigned)rev[i + 1][j - 1] + (unsigned)rev[i + 1][j + 1]) / 6;
            }
            //Bottom row of image
            else if(i == height - 1)
            {
                if(j == 0)
                    sum = ((unsigned)rev[i][j] + (unsigned)rev[i][j + 1] + 
                            (unsigned)rev[i - 1][j] + (unsigned)rev[i - 1][j + 1]) / 4;
                else if(j == width - 1)
                    sum = ((unsigned)rev[i][j] + (unsigned)rev[i][j - 1] +
                            (unsigned)rev[i - 1][j] + (unsigned)rev[i - 1][j - 1]) / 4;
                else
                    sum = ((unsigned)rev[i][j] + (unsigned)rev[i][j - 1] + (unsigned)rev[i][j + 1] +
                            (unsigned)rev[i - 1][j] + (unsigned)rev[i - 1][j - 1] + (unsigned)rev[i - 1][j + 1]) / 6;
            }
            //Left side of image (excluding top or bottom row)
            else if(j == 0)
                sum = ((unsigned)rev[i][j] + (unsigned)rev[i - 1][j] + (unsigned)rev[i + 1][j] +
                        (unsigned)rev[i][j + 1] + (unsigned)rev[i - 1][j + 1] + (unsigned)rev[i + 1][j + 1]) / 6;
            //Right side of image (excluding top or bottom row)
            else if(j == width - 1)
                sum = ((unsigned)rev[i][j] + (unsigned)rev[i - 1][j] + (unsigned)rev[i + 1][j] + 
                        (unsigned)rev[i][j - 1] + (unsigned)rev[i - 1][j - 1] + (unsigned)rev[i + 1][j - 1]) / 6;
            rev[i][j] = (unsigned char)sum;         
        }
    }

    for(i = 0; i < height; i++)
    {
        for(j = 0; j < width; j++)
        {
            if(j < width && i < height)
                fwrite(&rev[i][j], sizeof(char), 1, fout);
        }
    }

    fclose(fout);
    fclose(fin);

    return 0;
}

注意：此代码仅适用于.raw灰度图像。

编辑：我已经对图像的其余部分进行了模糊处理，但仍然没有获得可读的输出文件。我不确定我的算法是否正确，因为我不太熟悉将字节加在一起。

Answer 1

这部分

rev = (char **)malloc(height * sizeof(char *));
for(i = 0; i < width; i++)
    rev[i] = (char *)malloc(width * sizeof(char));

我认为你的意思是

for(i = 0; i < height; i++)

其他错误：

您可能希望使用unsigned char作为数据类型
请勿使用sum +=，请使用sum =
您只对图像的第一行进行模糊计算
您可能希望将计算中使用的每个输入转换为unsigned，否则值将溢出

尝试：

for(i = 0; i < (height - 1); i++)
{
    for(j = 0; j < (width - 1); j++)
    {
        sum = ((unsigned) rev[i][j] + (unsigned) rev[i][j + 1] + 
          (unsigned) rev[i + 1][j] + (unsigned) rev[i + 1][j + 1]) / 4;
        rev[i][j] = (unsigned char) sum;
    }
}

模糊图像滤镜 - C.

1 个答案: