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T 11/1/05
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HW due:
Finish the bitmap problem from yesterday’s test, showing your intermediate
binary decoding and your 6 by 15 grid.
Here is the protocol:
(a) All values are to be interpreted in big-endian style.
(b) Convert first to binary.
(c) 00 = white, 01 = black, and 11 = escape
The escape code indicates that a repeat
count and color value will follow.
The repeat count is 4 bits (0001
to 1111) denoting the number of times that
the next 2 bits thereafter (00 or
01) are to be repeated as colors.
(d) Bitmap is 6 rows by 15 columns.
Here are the data (in hex):
75 1D 44 54 05 D4 45 11 1D 4D 10 41 14 11 75 11 01 17 51 11 11
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W 11/2/05
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HW due: The
HW due yesterday will be collected. (Stephen has already turned his in.) Your
substitute teacher for today is Mr. Kelley. During class, you will perform a
“round robin protocol and bitmap exercise” as follows:
1. Write out a protocol for all 4 other students that will define a bitmap of
6 by 15 or larger. (Be sure to state the dimensions.)
2. Share your protocol and byte stream (in hex) with all the other students.
3. Solve everyone else’s bitmap.
4. Make a bitmap for each other person to solve (in his protocol). You
should be the one to check that he solves it correctly.
5. Mark “author name” and “solver name” on each sheet and hand everything in
to Mr. Kelley.
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Th
11/3/05
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No additional HW due.
However, since nobody followed the instructions for yesterday’s class that
was supervised by Mr. Kelley, the scores on that assignment will be rather
low.
In class: JPEG, MPEG, bandwidth issues.
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F 11/4/05
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No school.
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M 11/7/05
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HW due: Read
the following articles about JPEG and image compression. Read the first two
thoroughly, read the third one for the text (glossing over the mathematical
terminology such as “orthonormal basis”), and skim
the fourth one, since it is quite technical. Then answer the study questions
that follow. (MPEG is considerably more difficult. We will cover MPEG in
class, in rough terms only.)
http://uk.news.yahoo.com/10102005/372/image-compression.html
(read thoroughly)
http://digitalphotography.weblogsinc.com/entry/1234000663057679/
(read thoroughly)
http://www.mir.com/DMG/ycbcr.html
(read text, skim the mathematics)
http://www.jpeg.org/public/jfif.pdf
(skim)
1. What is the difference between raster and vector format for images?
2. Which is better for most photographic applications, raster or vector?
3. Which is better from a compression standpoint, raster or vector?
4. What are the advantages of TIFF? of PNG?
5. What happens if you open a JPEG file, edit it, save it as a new JPEG, and
repeat this process a few times?
6. If RGB color is encoded at 3 bytes per pixel, what color pixel is
represented by 0xFFFFFF?
7. What is a colorspace?
8. What are the key differences between RGB and YCbCr
color encoding?
9. Prove that the system of linear equations that converts RGB to YCbCr (see fourth link above) can be solved by linear
algebra to produce the second system, namely the system that converts YCbCr back to RGB. In other words, take the first set of
3 equations as a given (namely, Y = .299R + .587G + .114B, Cb = –.1687R – .3313G + .5B + 128, and Cr = .5R – .4187G
– .0813B + 128). Assume that Y, Cb, and Cr are
constants. Then, using the techniques that you learned in Algebra II, solve
for R, G, and B. Your answer, after some algebra, should match the second set
of equations given, except for a small amount of roundoff
error. This sounds terribly complicated, but in fact, a good Algebra II
student should be able to accomplish it with a little patience.
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T 11/8/05
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No additional HW due. The
questions due yesterday will be collected and graded on a 20-point scale. Try
to do a better job on them. (For example, question #1 should be fleshed out
into a full paragraph in light of Monday’s class discussion.) I will be
available in the Math Lab for additional help. Students
sick yesterday should get notes from the people who were there.
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W 11/9/05
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HW due:
Read this
snippet about animation and graphic special effects, starting with the word
BITMAP and ending at the first yellow box. Then skim this article.
(I don’t recommend reading the second reference thoroughly, since it’s highly
technical. At a minimum, read the first few paragraphs and the subheadings.
Unless you have programmed in TI-83 assembly language, the coding examples
will look like gibberish to you.)
Answer the following questions:
1. How is the word BitBlt pronounced?
2. What does BitBlt mean?
3. Fill in the blank: Vector graphics must be __________ as bitmaps before
they can be displayed by most hardware devices.
4. What is a rare term that means the same as “bitmap” but more accurately
describes what a bitmap is?
5. What is a sprite?
6. What logical operation (AND, OR, NOT, NOR, NAND, XOR, XNOR, etc.) is most
closely associated with the display of sprites?
7. What possible advantage does the operation you identified in #1 provide?
Think about your answer.
8. Would the development of modern video games have been possible without
sprites? Explain your answer.
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Th
11/10/05
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HW due:
Please revisit your HW from yesterday, making sure that it is complete and
correct. Three-hole punched paper is required for full credit. Then, complete
as much of the STA Mathcross
#1 as possible. You may seek help from your classmates, from your
parents, and from the Internet, but not from students of mine in other
classes. There will be a prize for the best entry.
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F 11/11/05
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Unit Quiz
on digital video (topics 0x51–0x5F, plus
0x48 and 0x4E).
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M 11/14/05
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No additional HW due.
Finish your STA Mathcross
#1 if you have not already done so.
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T 11/15/05
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HW due:
Read pp. 134-139, 637-640. Three of these pages were previously assigned for
Sept. 23.
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W 11/16/05
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HW due:
Convert the following decimal problems into two’s complement (1-byte binary or
hex, your choice). You may use the Windows Calculator (CALC.EXE) to check
your work. Show all the components, i.e., the addends as well as the answer.
Use a vertical format and show your work.
1. 58d – 14d = 44d
2. –22d + 122d = 100d
3. –118d – 16d = overflow (How can we detect this?)
4. 96d + 80d = overflow (How can we detect this?)
5. 38d – 64d = –26d
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Th
11/17/05
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HW due:
Read pp. 643-650 and do the following problems in two’s complement. Use 2-byte hex notation throughout, with
leading zeros if necessary. It is assumed that you will use the Windows
Calculator (CALC.EXE) to perform the hex conversions. Use a vertical format
and show your work.
1. 2005d – 1932d = 73d
2. –555 + 1155d = 600d
3. –21 – 32,750d = overflow (Write out a sentence explaining how we can
detect this.)
4. 20,000d + 21,000d = overflow (Write out a sentence explaining how we can
detect this.)
5. 9495d – 9991d = –496d
After you have completed this technical work, your optional fun homework is
the STA Mathcross
#1 or the brand-new STA Mathcross #2.
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F 11/18/05
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HW due:
Read pp. 643-650 again and take some helpful reading notes. There will be an open-note
quiz on the most important aspects of this reading. Obviously, I can’t ask
you to perform detailed conversions just yet, since we have not discussed
floating-point formats. However, I can certainly ask you to explain what is
meant by overflow (p. 644), underflow (p. 645), a normalized floating-point
number (p. 646), or the expression NaN (p. 650).
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M 11/21/05
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HW due:
Read this
group of slides on binary coded decimal (BCD), which includes an overview
of sources of error and various numeric and text encoding schemes. There will
be another open-note quiz on this material. The formulas will not be quizzed,
and you need not write them down or memorize them. Answer the following
questions as part of your homework:
1. How would you add the numbers 15 and 23 in BCD? Hint: It’s both easier and harder than adding in hex or binary.
You may find this
article helpful, and you may ignore everything having to do with BCD
subtraction, nine’s complement, and ten’s complement.
2. Why is math with BCD slower than math in binary?
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T 11/22/05
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HW due:
First, turn in yesterday’s written assignment (2 questions) to Mr. Kelley.
In class: First, solve the following decimal addition problems using 10’s
complement arithmetic padded out to 4 decimal
positions. Show your work. If overflow occurs, describe clearly how you can
tell. You may work together, but each student must submit a paper. There is
no binary or hex arithmetic in this assignment. The purpose is to see whether
you can generalize what Paul discovered yesterday about 9’s complement and
10’s complement, applying the ideas from 1’s and 2’s complement. This
exercise is a simulation of the logic that would be employed by an
implementation of BCD. In 10’s complement, numbers from 0000 to 4999 are to
be treated normally, but 5000 represents –5000, 5001 represents –4999, 5002
represents –4998, and so on up to 9999 representing –1. Turn in your papers to Mr. Kelley.
1. 0347 – 1142
2. –2144 + 3848
3. 0016 – 0035
4. 4670 + 0350 (overflow)
5. –3838 – 3878 (overflow)
6. 1553 + 1698 (easy, boring)
Then, when you have finished those, work on the STA Mathcross #4,
which has a number of MODD clues. Other students will be asking you for help
on this one during the first week back.
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Thanksgiving break.
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M 11/28/05
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HW due: Outline
of your 10-minute talk that you will be giving on Dec. 13. At least one neat handwritten page
(or approximately half of a page, typed) is expected. Cut-and-paste from Wikipedia (or wherever) is not acceptable. Bulleted lists
and sentence fragments are acceptable, however, provided they show actual
“meat” (content), not simply a lot of empty words.
This HW assignment will be worth 20 points and will be evaluated based on the
following criteria:
1. Evidence that you have found facts that are of interest to you.
2. Evidence that you have given at least some attention to finding facts of
interest to your classmates.
3. Evidence of an attempt to reduce the scope to something that can be
summarized in 10 minutes.
Note: Even though your presentation
on Dec. 13 will last only 10 minutes, you need to do considerably more
background reading so that you will be the most knowledgeable person in the
room on your topic. Remember, this is what teachers have to do all the time.
If you decide that you want to change topics, send me an e-mail by late
Sunday afternoon so that I can respond to your request. I will approve your
request if it is reasonable and does not clash with other students’ topics.
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T 11/29/05
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HW due:
Read this article on DES.
Although it is somewhat out of date, it is much more readable than the Wikipedia articles on DES and AES,
which you should only skim. Once again, there will be an open-notes quiz to
check for basic understanding.
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W 11/30/05
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HW due:
Work through the first few screens of the DES procedure in yesterday’s article, going
only through the line marked
K+ =
that is about 5 screens down from the top. I recommend that you work through
to this point using the example provided. Then, as your written homework,
compute the 56-bit K+ that results if we start with the key FACE1DEAD2CAB0BA
instead of the example provided (namely, 133457799BBCDFF1). For convenience
in checking, give your answer in hex.
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