# Assignment 7 FAQ and Student Discussion Page

The course staff will post answers to frequently asked questions about assignment 7 here. Feel free to add to this page yourself if you've got information to share with the rest of the class. Remember, the quickest way to get a response from a TA is to post to cs148-win0607-staff@lists.stanford.edu

## What are the minimum requirements for our quantization scheme?

Any quantization scheme that provides some form of quality control is fine. The simplest method, which is mentioned in the assignment, of just converting back to an STPixel is **not** sufficient since there is no quality control. While not required, we suggest you experiment with this a bit to find a scheme that gives some intuitive control over quality.

## I'm confused about what you are asking in Question 2

The wavelet transform projects the image onto a wavelet basis. Each term corresponds to a wavelet basis image. These are the 2D versions of the 1D basis functions shown in the lecture (slide 26, right column). The first graph shows the scaling function, the second shows the first detail basis function, the third and fourth show the next, higher frequency basis functions. Notice that the higher frequency terms changes values faster. This indicates it will have higher frequencies in its Fourier transform. The question is asking you to consider the Fourier transform of the second (low frequency) detail term. Does the Fourier transform contain only low frequencies? What features about the graph indicate this?