Digital Information

An author is preparing to send their book to a publisher as an email attachment. The file on their computer is 1000 bytes. When they attach the file to their email, it shows as 750 bytes. The author gets very upset because they are concerned that part of their book has been deleted by the email address. If you could talk to this author, how would you explain what is happening to their book?

I would explain that the words or phrases that they used many times in her book have been coded into a lawless compression. None of their writing was lost but the computer just compressed it by using shorter variable write ins for repeated words and phrases. When arrives at the email address of the person they are sending it to. The computer will translate it right back to the original. (answers may vary)

Describe how the process of sampling, RGB pixels, and binary sequences work together to display a digital color image.

The computer goes line by line copy the color using RGB pixels. The way they represent the colors is using is using a certain about of 1's and 0's to represent each pixel. The more 1's and 0's used to represent a pixel, the clearer/ accurate the image will be. (answers may vary)

What is the most important quality of lossless compression? a.)The data is transformed to usually make it smaller. It can always be re-constructed back to the original. b.)The data is transformed to always make it smaller. It can always be re-constructed back to the original. c.)The data is transformed to usually make it smaller. It cannot always be re-constructed back to the original. d.)The data is transformed to always make it smaller. It cannot always be re-constructed back to the original.

The correct answer is: a a.)The data is transformed to usually make it smaller. It can always be re-constructed back to the original.

Which of the following would result in a better digital approximation of an analog black and white image? a.)Increasing the size of each sample square, thus decreasing the number of samples taken. b.)Decreasing the size of each sample square, thus increasing the number of samples taken. c.)Using fewer bits to represent the image. d.)Using decimal numbers to represent each pixel.

The correct answer is: b Decreasing the size of each sample square, thus increasing the number of samples taken.

Which statement about analog and digital images is true? a.)With advances in technology, digital images look exactly like the analog images they represent. b.)Sampling an analog image more frequently produces a digital image with a better representation. c.)Analog images come from data that is measured at regular intervals. d.)Digital images come from data that is measures continuously.

The correct answer is: b b.)Sampling an analog image more frequently produces a digital image with a better representation.

Assume your friend just sent you 32 bits of pixel data (just the 0s and 1s for black and white pixels) that were encoded after sampling an image. Choose the two statements that are true. a.)The 32 bits of pixel data is enough to produce the image using the widget. Nothing else is needed. b.)The digital image would be an exact copy of the analog image. c.)The correct width and height must be input into the pixelation widget to produce the image. d.)The fact that only 32 bits were used to represent the image indicates relatively large sample squares were used. The digital image may vary from the analog image significantly.

The correct two are: c and d c.)The correct width and height must be input into the pixelation widget to produce the image. & d.)The fact that only 32 bits were used to represent the image indicates relatively large sample squares were used. The digital image may vary from the analog image significantly.

Your computer science teacher asks you to sample a black and white image that is 4" x 6". How would you sample the image to provide a good digital approximation using the pixelation widget? What sample size would you use? How would your decision affect the digital representation?

You would do 16x2 because that is 4x the analogue images size. (answers may vary)