Stanford University

CS 131 Computer Vision: Foundations and Applications

Fall 2015-2016


CS 131 Frequently Asked Questions



Q1: CS131 is a relatively new course, offered for the first time in Fall 2013. Is this a re-numbering of CS231a (Introduction to Computer Vision)?

A: No. CS131 is an entirely new class. It is designed for undergraduate students, introducing them to the computer vision technology for the first time. CS231a will continue to be offered and continue to be a graduate level class. We hope that CS131, CS231a and CS231b (Cutting Edge Computer Vision) make a good series of computer vision class from introduction to cutting edge topics.


Q2: What are the prerequisites for CS131?

A: We hope that you are familiar with:

--College level calculus (e.g. MATH 19 or 41) - You’ll need to be able to take a derivative, and maximize a function by finding where the derivative=0.

--Linear algebra (e.g. MATH 51) - We will use matrix transpose, inverse, and other operations to do algebra with matrix expressions. We’ll use transformation matrices to rotate/transform points, and we’ll use Singular Value Decomposition. (These topics are important for the homeworks, but if you are a quick learner you should be able to learn them during the class if you haven’t yet. We will have review sessions and provide review materials.)

--Basic probability and statistics (e.g. CS 109 or other stats course) - You should understand conditional probability, mean, and variance.

--We also require a decent amount of programming skills, such as entry-level Matlab, and the ability to work in the Linux environment. If you are unsure about your background, we encourage you to try out Problem Set 0, which is a “normalizing” problem set for the class. PS0 will help you gauge if CS131 is the right level for you.


Q3: What's the collaboration policy for Problem Sets (both theoretical problems and programming assignments)?

A: Study groups are allowed, but we expect students to understand and complete their own problem set and to hand in one problem set per student. If you worked in a group, please put the names of your study group on your solution when you hand in the problem set. Also, please put number of late days used in the problem set. Finally, we expect students to not look at implementations online. Just like all other classes at Stanford, we take the student Honor Code extremely seriously.


Q4: Where do I find the latest announcements, lecture notes, syllabus and course information in general?

A: The lecture notes and syllabus are on the course web page:
Announcements and discussion are at the Piazza forum:


Q5: I have a question about the class (homework, programming issues, looking for study groups, etc.). What is the best way to reach course staff and my classmates?

A: The class forum on Piazza! If you have personal issue to discuss with the course staff, please email:

Q6: Can I take this course on a credit/no credit basis?

A: Yes. Credit will be given to those who would have otherwise earned a C- or above.


Q7: I am not taking CS131 for credit; can I audit or sit-in?

A: In general we are very open to sitting-in guests if you are a member of the Stanford community (registered student, staff, and/or faculty). Out of courtesy, we would appreciate that you first email or talk to the instructor after the first class you attend.


Q8: How do I submit a Problem Set outside class?

A: There is a submission cabinet in the Gates building, near the east entrance. You can find a photo of it here. Note that the building's outer doors lock at 5:30pm, so you won't be able to access the cabinet after that time. Please do not email your Problem Sets to us. Please remember to write down the date and time of submission as well as the number of late days you are using for that problem set, if any.


Q9: I would like to come to a TA homework session after business hours but I do not have a key to the Gates building. What should I do?

A: Your Stanford ID card can be used as a key to get into the basement of Gates. The room where the homework session is held, Gates 104, can be accessed from the basement; come from the corner entrance to the basement and knock on the door! Then, one of the TAs should open the door for you.


Q10: Why can the course be taken for either 3 or 4 units? Is there a difference in the requirements?

A: There is no difference in terms of workload. (The lower unit option is to accommodate students who have per-quarter unit limits.)

Q11: Are the lectures and TA sessions videotaped?

A: No. Please come to class in person.