在C++中读取bmp文件的宽和高

#pragma pack(push, 1)
struct BMPFileHeader {
    char signature[2];
    uint32_t fileSize;
    uint32_t reserved;
    uint32_t dataOffset;
};
#pragma pack(pop)

#pragma pack(push, 1)
struct BMPInfoHeader {
    uint32_t headerSize;
    int32_t width;
    int32_t height;
    uint16_t planes;
    uint16_t bitCount;
    uint32_t compression;
    uint32_t imageSize;
    int32_t xPixelsPerMeter;
    int32_t yPixelsPerMeter;
    uint32_t colorsUsed;
    uint32_t colorsImportant;
};
#pragma pack(pop)

#include <iostream>
#include <fstream>

#pragma pack(push, 1)
struct BMPFileHeader {
    char signature[2];
    uint32_t fileSize;
    uint32_t reserved;
    uint32_t dataOffset;
};
#pragma pack(pop)

#pragma pack(push, 1)
struct BMPInfoHeader {
    uint32_t headerSize;
    int32_t width;
    int32_t height;
    uint16_t planes;
    uint16_t bitCount;
    uint32_t compression;
    uint32_t imageSize;
    int32_t xPixelsPerMeter;
    int32_t yPixelsPerMeter;
    uint32_t colorsUsed;
    uint32_t colorsImportant;
};
#pragma pack(pop)

int main() {
    std::ifstream file("example.bmp", std::ios::binary);
    if (!file) {
        std::cout << "Failed to open bmp file." << std::endl;
        return 1;
    }

    BMPFileHeader fileHeader;
    BMPInfoHeader infoHeader;

    file.read(reinterpret_cast<char*>(&fileHeader), sizeof(BMPFileHeader));
    file.read(reinterpret_cast<char*>(&infoHeader), sizeof(BMPInfoHeader));

    std::cout << "Width: " << infoHeader.width << std::endl;
    std::cout << "Height: " << infoHeader.height << std::endl;

    file.close();

    return 0;
}