AP COMP SCI QUIZ PRACTICE FLEX WEDNESDAY JAN 27TH 2021

Abe buys a single-user license for a piece of software. Which of the following best describes how Abe can legally install this software?

ANSWER: Abe can install this software on his personal computer. He may be able to install it on other personal devices only he uses if the license terms allow this. EXPLANATION: This is correct. A single-user license restricts the software to be used by just one person. Some licenses however allow a single user to use the software on multiple different devices. The exact conditions allowing or restricting this usage can be read in the license agreement.

Which of the following terms specifically refers to images which are stored as a set of digital values called pixels?

ANSWER: RASTER IMAGES EXPLANATION: This is correct. Raster image is the correct term for an image which is stored using pixels. The file formats PNG, JPG and PNG are all examples of raster image formats.

Which of the following statements about lossless image formats, like PNG, and lossy image formats, like JPEG, is true?

Lossy image formats sacrifice detail within an image in order to achieve smaller file sizes.

Binary numbers are essential to computing and can be used to represent several types of data including images, numbers, sound, and text. If 1001011 represents a number, which of the following numbers is the hexadecimal equivalent to that number? Use the following table as a reference.

ANSWER: 4B EXPLANATION: This is correct. Every single hexadecimal digit is equivalent to exactly 4 binary digits. To convert a binary number into a hexadecimal number, begin from the right splitting the binary number into groups of 4, adding extra 0s to the start if necessary. The binary number 1001011 is rewritten this way: 0100 1011. The 4 digit binary number 0100 is equivalent to 4 in both decimal and hexadecimal representations, 1011 is equivalent to the decimal number 11, which is equivalent to B in hexadecimal. Therefore the binary number 1001011 is written as 4B using hexadecimal.

Mrs. Morgan is a teacher in a small, rural town. Her school's technology budget is very limited but she wants to use technology to enhance her instruction. Below is a list of actions she considers taking to utilize technology in her classroom. Which of these actions is likely to violate copyright law? I. Playing her class a scene from a dvd she owns on a school television.II. Distributing a link to a free educational app which students can download on their phones.III. Installing a software package which she has a personal license to use onto the classroom computers for students to use.

ANSWER: III only EXPLANATION: This is correct. The use of a single scene from a dvd for educational purposes would likely not breach copyright law as there are specific exemptions covering this. Likewise, encouraging students to download a free program on personal devices would not breach copyright law, although there could be restrictions against directly distributing it to the students. However installing software on shared organizational computers would breach the terms of a personal license and therefore be against copyright law.

Central High School has a graphics design course that is developing a historical online archive of the school. The original photos of the school and its history are being digitally scanned and will be placed onto the archival website they are creating. Although the files will be initially scanned in an uncompressed format, the photos uploaded to the website need to have much smaller file sizes and do not need to be of the best quality. Which of the following file formats would be best to use for the photos on the website?

ANSWER: JPEG EXPLANATION: This is correct. JPEG images use lossy compression which results in a great deal of quality loss, but gives a very small file size. This makes it ideal for storing images when small file sizes are desired and quality is less important. As JPEG also uses a large color palette it is generally well suited for displaying photographs where there are many colors blending into one another.

Consider the following procedures for accessing and modifying the color channels of an RGB pixel. RED (pixel): Extracts the red value from the color of pixel GREEN (pixel): Extracts the green value from the color of pixel BLUE (pixel): Extracts the blue value from the color of pixel SETCOLOR (pixel,r,g,b): Replaces the red, green, and blue values of pixel with new values (r, g, and b, respectively) Using the above procedures, a programmer has written the following code segment to modify image, an array representing the color values for each pixel within an RGB image. FOR EACH pixel IN image { r ← RED(pixel) g ← GREEN(pixel) b ← BLUE(pixel) avg ← (r + g + b) / 3 SETCOLOR (pixel, avg, avg, avg) }

ANSWER: The resulting image will be a grayscale version of the original image. EXPLANATION: When extracting the red, green and blue components from the pixel, we are summing all three values together and then dividing by 3. This is the exact process we would use in math in order to average numbers. What this will do is average the components together AND then set each component back to that value. Whenever a pixel shares the same red, green and blue value, it is a shade of gray (white up to black). So therefore this would be a grayscale image.

While developing a program, you find a similar project that someone has created and posted online. It contains a number of elements (e.g., images, music, code segments, etc.) that you would like to integrate into your own project. Under what conditions may you reuse these elements in your work?

ANSWER: You may only reuse elements for which the original owner has granted a license to reuse, such as Creative Commons Share Alike license. EXPLANATION: This is correct. Certain licenses are specifically designed to allow people to reuse work. There are normally some conditions on what exactly can be done with the work.