error: (-215:Assertion failed) src1.type() == CV_32FC1 || src1.type() == CV_64FC1 in function 'cv::phaseCorrelate'

This error occurs when trying to use the phaseCorrelate function in OpenCV and the input images are not of the correct data type. The function requires that the input images be of type CV_32FC1 or CV_64FC1, which are single-channel floating point images of either 32 or 64 bits.

To fix this error, you need to convert the input images to the correct data type before passing them to the phaseCorrelate function. You can use the cv::cvtColor function to convert the images to grayscale, and then use cv::convertTo to convert them to the correct data type.

Here's an example of how to do this:

cv::Mat image1 = cv::imread("image1.jpg", cv::IMREAD_GRAYSCALE);
cv::Mat image2 = cv::imread("image2.jpg", cv::IMREAD_GRAYSCALE);

cv::Mat floatImage1, floatImage2;
image1.convertTo(floatImage1, CV_32FC1);
image2.convertTo(floatImage2, CV_32FC1);

cv::Point2d phaseShift = cv::phaseCorrelate(floatImage1, floatImage2);

In this example, we first load the input images as grayscale using cv::imread. We then convert them to the CV_32FC1 data type using cv::convertTo. Finally, we pass the converted images to the phaseCorrelate function to calculate the phase shift between the two images.