im = imread('G:\matlab学习\图像匹配\matlabcode\examples-code\al.tif','tif');

As an AI language model, I cannot access your local directory or files. The `imread` function is used in MATLAB to read an image from a file. The first argument is the file path, and the second argument is the file format. In this case, the image file is located at `G:\matlab学习\图像匹配\matlabcode\examples-code\al.tif` and the file format is `tif`.