如何利用exiv2库输入gps数据到图片

您可以使用以下代码将GPS数据输入到图片中：

#include <exiv2/exiv2.hpp>

int main(int argc, char* argv[]) {
    try {
        // Open the image file
        Exiv2::Image::AutoPtr image = Exiv2::ImageFactory::open(argv[1]);

        // Read the metadata
        image->readMetadata();

        // Create a GPSInfo structure
        Exiv2::gpsInfo gps;
        gps.latitude = Exiv2::Rational(37, 1);
        gps.longitude = Exiv2::Rational(-122, 1);
        gps.altitude = Exiv2::Rational(50, 1);

        // Set the GPSInfo in the image metadata
        Exiv2::ExifData& exifData = image->exifData();
        exifData["Exif.GPSInfo.GPSLatitude"] = gps.latitude;
        exifData["Exif.GPSInfo.GPSLatitudeRef"] = "N";
        exifData["Exif.GPSInfo.GPSLongitude"] = gps.longitude;
        exifData["Exif.GPSInfo.GPSLongitudeRef"] = "W";
        exifData["Exif.GPSInfo.GPSAltitude"] = gps.altitude;

        // Write the metadata to the image file
        image->writeMetadata();

        return 0;
    }
    catch (std::exception& e) {
        std::cerr << "Error: " << e.what() << std::endl;
        return 1;
    }
}

这个程序使用exiv2库打开一个图片文件，读取元数据，然后创建一个GPSInfo结构体，将GPS数据设置到结构体中，最后将GPS数据写入图片的元数据中。