How to pass data to Mat using pointer of image data

Question

In my code, I don't want to read data from rout of images,such as

    cv::Mat img_1 = imread("F:\1.tif");

Instead I wanna read data from pointer:

    float* srcImage;//pointer to image data
    cv::Mat img_1(height, width, CV_32FC1, srcImage);

However, I found that, by this way, when I used the img_1 in the following ORB function, it didn't work

    cv::ORB orb;
vector<cv::KeyPoint> keyPoints_1;
cv::Mat descriptors_1;
orb(img_1, cv::Mat(), keyPoints_1, descriptors_1);

How can I pass data to Mat from pointer? Is there any difference between imread() function and pass data from pointer? Or, is there any special request in cv::ORB function ?

Thanks very much! I'm not familiar with OpenCV, I just start using it for a few weeks, I just need solve this problem and the rest part of my code depends on results of this part.

Answer 1

orb wants an 8bit grayscale image as input, not a CV_32FC1