获取 OpenCV 图像类型的枚举名称（例如 CV_32FC1）？

Question

在 OpenCV 的 C++ 接口中，检查图像的类型似乎很容易。如果您有图像cv::Mat img = cv::imread("someImage.xyz")，则只需使用int theType = img.type()。

但是，正如您所料，调用 img.type() 只会给出一个整数，而不是枚举名称（例如 CV_32FC1）。

如果我知道 OpenCV 枚举的整数值，是否有一种简单的方法可以打印出枚举名称（例如 CV_32FC1）？

Answer 1

据我所知，OpenCV 中不存在这样的功能。

我认为你最好编写自己的函数来获得这些。很多开关盒，但我想它可以完成工作。枚举可以找到here。

编辑：

这是你可以用来提取类型的东西。我猜可能有一种更有效的方法，但我现在无法理解它。

std::string getImageType(int number)
{
    // find type
    int imgTypeInt = number%8;
    std::string imgTypeString;

    switch (imgTypeInt)
    {
        case 0:
            imgTypeString = "8U";
            break;
        case 1:
            imgTypeString = "8S";
            break;
        case 2:
            imgTypeString = "16U";
            break;
        case 3:
            imgTypeString = "16S";
            break;
        case 4:
            imgTypeString = "32S";
            break;
        case 5:
            imgTypeString = "32F";
            break;
        case 6:
            imgTypeString = "64F";
            break;
        default:
            break;
    }

    // find channel
    int channel = (number/8) + 1;

    std::stringstream type;
    type<<"CV_"<<imgTypeString<<"C"<<channel;

    return type.str();
}

Answer 2

按照@Bob 的建议，我编写了自己的函数来解决这个问题。这里是：

// take number image type number (from cv::Mat.type()), get OpenCV's enum string.
string getImgType(int imgTypeInt)
{
    int numImgTypes = 35; // 7 base types, with five channel options each (none or C1, ..., C4)

    int enum_ints[] =       {CV_8U,  CV_8UC1,  CV_8UC2,  CV_8UC3,  CV_8UC4,
                             CV_8S,  CV_8SC1,  CV_8SC2,  CV_8SC3,  CV_8SC4,
                             CV_16U, CV_16UC1, CV_16UC2, CV_16UC3, CV_16UC4,
                             CV_16S, CV_16SC1, CV_16SC2, CV_16SC3, CV_16SC4,
                             CV_32S, CV_32SC1, CV_32SC2, CV_32SC3, CV_32SC4,
                             CV_32F, CV_32FC1, CV_32FC2, CV_32FC3, CV_32FC4,
                             CV_64F, CV_64FC1, CV_64FC2, CV_64FC3, CV_64FC4};

    string enum_strings[] = {"CV_8U",  "CV_8UC1",  "CV_8UC2",  "CV_8UC3",  "CV_8UC4",
                             "CV_8S",  "CV_8SC1",  "CV_8SC2",  "CV_8SC3",  "CV_8SC4",
                             "CV_16U", "CV_16UC1", "CV_16UC2", "CV_16UC3", "CV_16UC4",
                             "CV_16S", "CV_16SC1", "CV_16SC2", "CV_16SC3", "CV_16SC4",
                             "CV_32S", "CV_32SC1", "CV_32SC2", "CV_32SC3", "CV_32SC4",
                             "CV_32F", "CV_32FC1", "CV_32FC2", "CV_32FC3", "CV_32FC4",
                             "CV_64F", "CV_64FC1", "CV_64FC2", "CV_64FC3", "CV_64FC4"};

    for(int i=0; i<numImgTypes; i++)
    {
        if(imgTypeInt == enum_ints[i]) return enum_strings[i];
    }
    return "unknown image type";
}

我是否忘记在查找表中包含任何 OpenCV 图像类型？