C语言计算DEM.tif填方挖方体积

#define _CRT_SECURE_NO_DEPRECATE #include <stdio.h> #include <stdlib.h> #include <sys/stat.h>

#define PIXEL_SIZE 30.0 // 像素大小 #define NO_DATA_VALUE -9999 // 无效像素值

int main() { FILE* fp_dem; const char* filename = 'D:\kjfx\dem.tif'; int width, height, i, j; float* elevation; float fill_volume = 0.0, cut_volume = 0.0;

// 打开DEM.tif文件
fp_dem = fopen(filename, 'rb');
if (fp_dem == NULL) {
    printf('Error: cannot open file %s!

', filename); return 1; }

// 读取DEM.tif文件头信息
fseek(fp_dem, 0x12, SEEK_SET);
fread(&width, 4, 1, fp_dem);
fread(&height, 4, 1, fp_dem);

// 计算DEM.tif文件大小
struct stat st;
if (stat(filename, &st) == 0) {
    long filesize = st.st_size;
}
else {
    printf('Error: cannot get file size!

'); return 1; } long datasize = st.st_size - 0x44;

// 检查文件大小是否符合要求
if (datasize % sizeof(float) != 0 || datasize / sizeof(float) != width * height) {
    printf('Error: invalid file size!

'); fclose(fp_dem); return 1; }

// 分配内存空间
elevation = (float*)malloc(datasize);
if (elevation == NULL) {
    printf('Error: cannot allocate memory!

'); fclose(fp_dem); return 1; }

// 读取DEM.tif数据
fseek(fp_dem, 0x44, SEEK_SET);
size_t n = fread(elevation, sizeof(float), datasize / sizeof(float), fp_dem);
if (n != datasize / sizeof(float)) {
    printf('Error: cannot read file!

'); free(elevation); fclose(fp_dem); return 1; }

// 遍历像素值，计算填方和挖方的体积
for (i = 0; i < height; i++) {
    for (j = 0; j < width; j++) {
        float elev1 = elevation[i * width + j];
        if (elev1 == NO_DATA_VALUE) {
            continue;
        }
        float elev2 = NO_DATA_VALUE;
        if (i > 0) {
            elev2 = elevation[(i - 1) * width + j];
            if (elev2 != NO_DATA_VALUE) {
                float diff = elev1 - elev2;
                if (diff > 0) {
                    cut_volume += diff * PIXEL_SIZE * PIXEL_SIZE;
                }
                else {
                    fill_volume += (-diff) * PIXEL_SIZE * PIXEL_SIZE;
                }
            }
        }
        if (i < height - 1) {
            elev2 = elevation[(i + 1) * width + j];
            if (elev2 != NO_DATA_VALUE) {
                float diff = elev1 - elev2;
                if (diff > 0) {
                    cut_volume += diff * PIXEL_SIZE * PIXEL_SIZE;
                }
                else {
                    fill_volume += (-diff) * PIXEL_SIZE * PIXEL_SIZE;
                }
            }
        }
        if (j > 0) {
            elev2 = elevation[i * width + j - 1];
            if (elev2 != NO_DATA_VALUE) {
                float diff = elev1 - elev2;
                if (diff > 0) {
                    cut_volume += diff * PIXEL_SIZE * PIXEL_SIZE;
                }
                else {
                    fill_volume += (-diff) * PIXEL_SIZE * PIXEL_SIZE;
                }
            }
        }
        if (j < width - 1) {
            elev2 = elevation[i * width + j + 1];
            if (elev2 != NO_DATA_VALUE) {
                float diff = elev1 - elev2;
                if (diff > 0) {
                    cut_volume += diff * PIXEL_SIZE * PIXEL_SIZE;
                }
                else {
                    fill_volume += (-diff) * PIXEL_SIZE * PIXEL_SIZE;
                }
            }
        }
    }
}

// 输出结果
printf('Fill volume = %.2f m3\n', fill_volume);
printf('Cut volume = %.2f m3\n', cut_volume);

// 释放内存空间
free(elevation);

// 关闭文件
fclose(fp_dem);

return 0;

}

// invalid file size怎么改正内容：可以尝试重新下载 DEM.tif 文件，确保文件大小和数据格式正确。如果问题仍然存在，可以检查代码中读取文件大小和数据大小的逻辑是否正确，或者尝试使用其他工具检查 DEM.tif 文件是否有效。