Questions for consultation: Please write your questions here.
Organizational Questions:
- Q: Can we use Calculator, because some of the calculations needed calculator to get answers?
- Q: Room for exam?
- Q: Do we need to answer the question in details or short answers?
- A: Short and concise is always preferred. The size of the text boxes or gaps indicate how much text is expected at maximum.
- Q: Can you please check some of the opal link for Tutorial solutions are not working?
- A: We are working on that. We already fixed everything up to solution 5. The rest will be fixed in the next minutes.
- Q: Paper will be on computer?
- A: Yes. Please see Exam FAQ in the Opal course "Method of examination".
- Q: Can we do some rough work? How will we do it on computer?
- A: We will provide you with blank sheets of paper, if you need.
Subject-related Questions:
- Q: Can you explain the digitization from graph?
- A: Explanation based on the task in Opal Tutorial 2, Task 1. Only the discrete values on the y-axis can be taken, no values in between (on y-axis). The x-axis has discrete steps at 0, 1, 2, 3, ... as the sampling frequency is 1Hz (1 sampling point per second). You just plot the discrete spots on the graph (e.g. drawn as small lollipop or circle). If you are in between two discrete y-values you take the one which is closer. Remember, sampling means discretization of the time axis. Quantization means discretization of the amplitude axis. Digitization = sampling + quantization.
- Q: Huffman Encoding
- A: Explained live using exercise slides.
- Q: Quantization tables for JPEG-compression? Tutorial 6 Task 2.
- A: Explained live using exercise slides.
- Q: In JPEG compression in which step the data reduction happens?
- A: In the quantization step mainly. Or in the chroma subsampling, when anything other than 4:4:4 is used.
- Q: Mid-Rise-Quantizer calculation. How can we calculate the resulting values after quantization?
- A: Explains Task5 b+c solution. Truncate means throw away everything after decimal point after the x/delta calculation
- Q: What is sgn(x) in mid-rise?
- A: It means signum (x), i.e. take the sign of the value. Positive values --> +1. Negative values --> -1.
- Q: Delta is 1 always?
- A: No. It can also be different from 1.
- Q: Will it be mentioned when different?
- A: Yes.
- Q: The chroma subsampling 4:2:0 what is the meaning of the 0 ? 4 is Y 2 is CbCr but 0 ?
- A: Explained live using exercise slides.