AP CSP Unit 2
With 32 bits, you can have possible dimensions 1x32, 2x16, 4x8. If you don't include width and height in your protocol, you can't know the size width and length. You can recover the original image. You can do this by setting the metadata to each of the possibilities, then seeing if the image makes sense.
Assume your friend just sent you 32 bits of pixel data (just the 0s and 1s for black and white pixels). Could you recover the original image? If so, how? If not, why not?
3,753 bytes (30,024 bits)
How many bytes does it take...? How many bytes (or bits) are required to encode an image that is 25 pixels wide and 50 pixels tall, if you encode each pixel with 3 bytes (24 bits) of RGB data. (Don't forget to add in the metadata! -- you should assume that we are using the file format used in this lesson with metadata that had 1 byte each for width, height and bits-per-pixel.)
The smallest possible image with only one pixel is 17 bits.
How many total bits would it take to represent the smallest possible image (i.e. an image with one pixel)?
There would be 65,041 bits.
How many total bits would there be in the largest possible image we could make with the pixelation widget (assuming 1 bit per pixel)?
To darken an image, you would have to decrease the value of green, red, and blue. Increase to lighten the photo. You can subtract 20 values down, but you would have to do that to all colors. To darken a grey, 000 would make is darker, and 111 would make it light.
Imagine that you have an image that is too dark or too bright. Describe how you would alter the RGB settings to brighten or darken it. Give an example.
Reasons why someone would choose to use lossy compression would be to not use so much space by taking out information that is not necessary, or wouldn't be noticed by a human. You can lose some photo quality that a human eye won't even notice. Why carry more on a file, if it won't even be noticed.
In general, what are reasons that someone would choose to use lossy compression? Write a brief response below including at least one example of a situation when lossy compression would be appropriate.
The largest dimensions we can make of an image with the pixelation widget is 255*255.
What are the dimensions (width and height) of the largest image we can make with the pixelation widget?
Lossless compression is fully reversible, meaning the original file can be recreated bit for bit.
Which of the following is true of lossy and lossless compression techniques? -Lossless compression throws away unimportant details that a human being will likely be unable to detect. - Lossy compression is only possible on files that are at least one gigabyte in size before compression. - Lossy compression techniques are no longer commonly used. - Lossless compression is fully reversible, meaning the original file can be recreated bit for bit.
Lossy compression is best suited for situations where some loss of detail is tolerable, especially if it will not be detectable by a human.
Which of the following is true of lossy and lossless compression techniques? - Lossless compression is only used in situations where lossy compression techniques can't be used. - Lossy compression is best suited for situations where some loss of detail is tolerable, especially if it will not be detectable by a human. -Both lossy and lossless compression techniques will result in some information being lost from the original file. -Neither lossy nor lossless compression can actually reduce the number of bits needed to represent a file.
