Exam Preparation Deck Flashcards
Describe the impulse response of the n-th order low pass filter.
Can be seen as a discrete sinc function, cut by a rectangular box. Impulse response is made causal by introduce a half window-size delay.
Describe the Hamming window function.
0.46 -> reverse 64… might be useful
Define the relation between cross-correlation sequence {c_{xy}(n)} and sequences {x_n}, {y_n}.
Cross-correlation is very close to convolution. From the equation, y_n is simply reversed.
What is the mapping between RGB and YUV?
This bookwork is unexpectedly required in many situations.
Not sure how to remember it… maybe the baby formula?
What is the mapping between YUV and YCrCb?
Why is it necessary?
From RGB -> YUV equation, U is bounded between +-0.7, and V between +-0.9. The mapping is used to normalize U, V. (2016)
Describe two types of logarithmic quantization.
How are they implemented?
mu-law and A-law. Both horribly hard to remember, but are asked in exams.
It is used to linearize quantization errors.
Define Steven’ law.
Define Weber’s Law.
State the Fechner’s scale.
A logarithmic relation between stimulus intensity and scale value.
Asserts that human perception is logarithmic instead of ^{n} where n < 1.
Describe the Direct form I, II implementation of:
Direct form II is simply swapping the two halves.
Define rectangular and sinc function in DSP.
It is possible for bandpass signals to be sampled without aliasing. What is the necessary condition?
How do you perform two real FFT simultaneously?
Typical complex number multiplication takes four real multiplications and two real additions.
How does the alternate method improve on that?
Three multiplications and five additions. May help when multiplication takes 3x times more time than addition.
Define the white noise signal
