4. A. What is compression?

Reduction of the space required for storage (of binary data) by an algorithm which converts the data to a smaller number of bits while preserving the information content.

b. Describe a benefit of compression.

To reduce the file size.

c. Describe dictionary-based compression.

Replace common sequence of character with a single codeword, or symbol that point to a dictionary of the original characters, or to the original occurrence of the word.

d. Describe run-length encoding.

A kind of compression algorithm which replaces sequences ("runs") of consecutive repeated characters (or other units of data) with a single character and the length of the run. This can either be applied to all input characters, including runs of length one, or a special character can be used to introduce a run-length encoded group. The longer and more frequent the runs are, the greater the compression that will be achieved. This technique is particularly useful for encoding black and white images where the data units would be single bit pixels.

5. a. One Hz is one cycle per second.

b. IPS. Instructions per second

c. Answer the following questions on the relationship of Hz to IPS.

i. Which is a better determiner of speed: MHz or IPS? MHz

ii. Does a high Hz equal a high IPS, and can they be inversely proportional? Explain.

High Hz unequal a high IPS, because Instructions can differ a great deal. Some complex instructions require a lot of cycles and take a comparatively long time to execute. Other instructions may be very simple and execute in very little time. For example, a division operation takes longer than an addition operation.

iii. How is it possible for a machine with a lower clock speed (Hz) to have a higher IPS than a machine with a higher clock speed?

Because Instructions can differ a great deal. Some complex instructions require a lot of cycles and take a comparatively long time to execute. Other instructions may be very simple and execute in very little time. For example, a division operation takes longer than an addition operation.

d. What is the relationship between the system clock and Hz?

One Hz means one system clock cycle per second.

6. Hexadecimal a. Define hexadecimal notation.

b. What advantages does hexadecimal have over binary?

Because it will takes more digits to express a value in binary notation than in hexadecimal notation, we have adopted hexadecimal notation as shorthand for binary so that we can express values more concisely.

c. Which number system, binary or hexadecimal, is used when referencing memory addresses and why? Hexadecimal

Decimal	Hexadecimal
15	F
99	63
191	BF
238	EE
16	10
107	6B
163	A3
221	DD

7. a. How are bitmapped images rendered?

Bitmap is composed to a grid of dots, and the color of each dot is stored as a binary number.

b. How are vectored images rendered?

Vectored images consist of a set of instructions for re-creating a picture. Instead of storing the color value for each pixel, a vector graphic file contains the instructions that the computer needs to create the shape, size, position, and color for each object in an image.

c. Which image type tends to be more photo-like in quality, bitmapped or vectored?

Bitmap tends to be more photo-like in quality. Since the bitmap is composed of pixels, so is the photo.

d. Which image type maintains a high image quality, regardless of how it is resized? Vectored images.

e. List three image editors.

CORELDRAW PHOTOSHOP ACDSEE32

8. a. Define I/O device.

Stands for input/output device.

b. Consider that a computer requires I/O devices to be able to interact with its environment. Explain why it is necessary for computers to have these devices.

c. Give four examples of I/O devices.

Digital camera, printer, speaker, keyboard.

d. For each I/O device in your answer to part c, explain the device's function from the perspective of a user.

Users take pictures with digital camera. It is stored in digital form, and can be uploaded onto a computer. The printer can print images or files. Keyboard is used to type data into computer. The speaker is the output device to enable the voice.