bmp图像平均滤波C语言

实现代码是什么？

以下是一个简单的C程序示例，用于实现BMP图像的平均滤波：

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

#pragma pack(push, 1)

typedef struct
{
    uint16_t bfType;
    uint32_t bfSize;
    uint16_t bfReserved1;
    uint16_t bfReserved2;
    uint32_t bfOffBits;
} BITMAPFILEHEADER;

typedef struct
{
    uint32_t biSize;
    int32_t  biWidth;
    int32_t  biHeight;
    uint16_t biPlanes;
    uint16_t biBitCount;
    uint32_t biCompression;
    uint32_t biSizeImage;
    int32_t  biXPelsPerMeter;
    int32_t  biYPelsPerMeter;
    uint32_t biClrUsed;
    uint32_t biClrImportant;
} BITMAPINFOHEADER;

#pragma pack(pop)

void convolve(unsigned char* img, int imgWidth, int imgHeight,
              unsigned char* kernel, int kernelWidth, int kernelHeight,
              unsigned char** output)
{
    int x, y, i, j, k;
    unsigned char acc;
    int kOffX = (kernelWidth / 2);
    int kOffY = (kernelHeight / 2);

    *output = (unsigned char*)malloc(imgWidth * imgHeight);
    memset(*output, 0, sizeof(unsigned char) * imgWidth * imgHeight);

    for (y = 0; y < imgHeight; y++)
    {
        for (x = 0; x < imgWidth; x++)
        {
            acc = 0;

            for (j = 0; j < kernelHeight; j++)
            {
                for (i = 0; i < kernelWidth; i++)
                {
                    int px = x - kOffX + i;
                    int py = y - kOffY + j;

                    if (px < 0 || py < 0 || px >= imgWidth || py >= imgHeight)
                        continue;

                    acc += img[py * imgWidth + px] * kernel[j * kernelWidth + i];
                }
            }

            (*output)[y * imgWidth + x] = acc / (kernelWidth * kernelHeight);
        }
    }
}

int main()
{
    BITMAPFILEHEADER fileHeader;
    BITMAPINFOHEADER infoHeader;

    FILE* f = fopen("input.bmp", "rb");
    if (!f)
        return -1;

    fread(&fileHeader, sizeof(fileHeader), 1, f);
    fread(&infoHeader, sizeof(infoHeader), 1, f);

    fseek(f, fileHeader.bfOffBits, SEEK_SET);

    int imgWidth = infoHeader.biWidth;
    int imgHeight = infoHeader.biHeight;
    int imgSize = imgWidth * imgHeight;

    unsigned char* img = (unsigned char*)malloc(imgSize);
    size_t bytesRead = fread(img, 1, imgSize, f);
    fclose(f);

    unsigned char kernel[] =
    {
        1, 1, 1,
        1, 1, 1,
        1, 1, 1
    };

    unsigned char* output;
    convolve(img, imgWidth, imgHeight, kernel, 3, 3, &output);

    f = fopen("output.bmp", "wb");
    if (!f)
        return -1;

    fwrite(&fileHeader, sizeof(fileHeader), 1, f);
    fwrite(&infoHeader, sizeof(infoHeader), 1, f);
    fwrite(output, 1, imgSize, f);
    fclose(f);

    free(img);
    free(output);

    return 0;
}

该程序的输入是名为“input.bmp”的24位BMP图像文件，它将进行平均值滤波，并生成名为“output.bmp”的输出文件。平滑卷积核的大小是3x3。请注意，此示例程序假定输入图像的大小与输出图像的大小相同，并且BMP文件中的图像数据以行为主序存储。实际的实现可能需要进行更多的健壮性检查和优化。