c++ - 如何在C ++中的opencv中打开两个透明图像

Question

我有 2 个透明图像，我希望它们在 opencv 的一个窗口中打开。下面的代码打开两个图像，但没有 alpha 通道，因为它使用 (CV_8UC3) 和那些透明的图像，我们应该使用 (CV_8UC4) 来显示透明度，但是当我将代码更改为 (CV_8UC4) 时，程序给了我一个错误。

我将在 (CV_8UC4) 的行上添加一个 #；

我会在错误行加上*；

//代码因为*和#变成了3部分。

这段代码适合我想做的事情吗？

此代码打开多个图像，但我已将其用于两个。

代码是：

void ShowManyImages(string title, int nArgs, ...) {
    int size;
    int i;
    int m, n;
    int x, y;

    // w - Maximum number of images in a row
    // h - Maximum number of images in a column
    int w, h;

    // scale - How much we have to resize the image
    float scale;
    int max;

    // If the number of arguments is lesser than 0 or greater than 12
    // return without displaying
    if (nArgs <= 0) {
        printf("Number of arguments too small....\n");
        return;
    }
    else if (nArgs > 14) {
        printf("Number of arguments too large, can only handle maximally 12 images at a time ...\n");
        return;
    }
    // Determine the size of the image,
    // and the number of rows/cols
    // from number of arguments
    else if (nArgs == 1) {
        w = h = 1;
        size = 300;
    }
    else if (nArgs == 2) {
        w = 2; h = 1;
        size = 1000;
    }
    else if (nArgs == 3 || nArgs == 4) {
        w = 2; h = 2;
        size = 300;
    }
    else if (nArgs == 5 || nArgs == 6) {
        w = 3; h = 2;
        size = 200;
    }
    else if (nArgs == 7 || nArgs == 8) {
        w = 4; h = 2;
        size = 200;
    }
    else {
        w = 4; h = 3;
        size = 150;
    }

    // Create a new 3 channel image
#   Mat DispImage = Mat::zeros(Size(100 + size*w, 60 + size*h), CV_8UC4);

    // Used to get the arguments passed
    va_list args;
    va_start(args, nArgs);

    // Loop for nArgs number of arguments
    for (i = 0, m = 20, n = 20; i < nArgs; i++, m += (0)) {
        // Get the Pointer to the IplImage
        Mat img = va_arg(args, Mat);

        // Check whether it is NULL or not
        // If it is NULL, release the image, and return
        if (img.empty()) {
            printf("Invalid arguments");
            return;
        }

        // Find the width and height of the image
        x = img.cols;
        y = img.rows;

        // Find whether height or width is greater in order to resize the image
        max = (x > y) ? x : y;

        // Find the scaling factor to resize the image
        scale = (float)((float)max / size);

        // Used to Align the images
        if (i % w == 0 && m != 20) {
            m = 20;
            n += 20 + size;
        }

        // Set the image ROI to display the current image
        // Resize the input image and copy the it to the Single Big Image
        Rect ROI(m, n, (int)(x / scale), (int)(y / scale));
        Mat temp; resize(img, temp, Size(ROI.width, ROI.height));
*       temp.copyTo(DispImage(ROI));
    }

    // Create a new window, and show the Single Big Image
    namedWindow(title, 1);
    imshow(title, DispImage);
    waitKey();

    // End the number of arguments
    va_end(args);
}

int main(int argc, char** argv)
{
    Mat img1 = imread("c:\\1.png");
    Mat img2 = imread("c:\\2.png");
    ShowManyImages("Image", 2, img1, img2);

    return 0;
} 

标签： c++opencv