SIFT pgm image problem

Hello sir, I want use SIFT tool for comparing 2 images. I have downloaded the code from our mathwork site. But the problem is when I run the code the dialog box appears which says "program to detect invariant keypoints in PGM images has stopped working". Can you please suggest me a solution. Its my collage project. Thank you

[John D'Errico]

Where did you download it from? There are MANY submissions on MATLAB CENTRAL that do SIFT. Please show a link.

[Nachiket Patki]

https://in.mathworks.com/matlabcentral/fileexchange/50319-sift-feature-extreaction?s_tid=answers_rc2-2_p5

This is the link sir.

[Nachiket Patki]

Please sir can you help me in this matter, I need find SIFT for my project.