Common compressed file formats and what they are used for
Name:
Date:
Class:
A
Quick Questions
Shade in the A or B circle for each question.
1. Which format is the better choice for a holiday photo you want to share online with a small file size?
2. Which format suits a school logo with sharp edges and flat colours?
3. Which statement is true?
4. You want to save a screenshot of an error message with readable text. Which format should you pick?
5. Which file type is a lossy format for music?
B
Match the Pairs
Draw a line connecting each item on the left to its match on the right.
| Left column | Right column | |
|---|---|---|
| 1photo.jpg | Asong.mp3 | |
| 2report.zip | BMP4 video is lossy, so the discarded data cannot be restored. Only lossless formats like ZIP or FLAC restore the original. | |
| 3A logo or screenshot with sharp edges and flat colours should be saved in a lossless format so it stays crisp | CJPEG is lossy, not lossless. It can blur the sharp edges of a logo, so PNG is the better choice. | |
| 4Music for a phone is often saved in a lossy format so the song takes up far less storage | Dschool_logo.png | |
| 5Save the school logo as JPEG because JPEG is lossless | EA JPEG photo: lossy compression gives a much smaller file by dropping detail the eye barely notices | |
| 6movie.mp4 can be restored exactly to the original video | FA ZIP archive: lossless compression that shrinks documents and can be unzipped to the exact original |
C
Definitions
Compressed file format
D
Fill in the Blanks
Complete each line of code by filling in the missing parts.
1.
photoFormat = "____"
compression = "lossy"
2.
logoFormat = "___"
compression = "lossless"
3.
musicFormat = "___"
compression = "lossy"
4.
videoFormat = "MP4"
compression = "_____"
5.
documentFormat = "___"
compression = "lossless"
E
Spot the Error
Shade in the letter of the line that contains an error.
Question 1
A
file = "beach.jpg"
B
if file.endswith(".jpg"):
C
print("Photo format")
D
print("Lossless")
Question 2
A
def best_for_logo()
B
fmt = "PNG"
C
print(fmt, "is lossless")
D
best_for_logo()
Question 3
A
music = song.mp3
B
lossy = True
C
if lossy:
D
print("Smaller file")
Question 4
A
docs = "essay.docx"
B
method = "lossy"
C
archive = "ZIP"
D
print(archive, method)
Question 5
A
video = "clip.mp4"
B
lossy = True
C
print("MP4 is lossless")
D
print("Good for video")
Answer Key
Common compressed file formats and what they are used for
Section A: Quick Questions
Q1
B — JPEG
Q2
A — PNG
Q3
A — PNG is lossless, so no image data is lost
Q4
A — PNG
Q5
B — MP3
Section B: Match the Pairs
Q1
photo.jpg → A JPEG photo: lossy compression gives a much smaller file by dropping detail the eye barely notices
Q2
report.zip → A ZIP archive: lossless compression that shrinks documents and can be unzipped to the exact original
Q3
A logo or screenshot with sharp edges and flat colours should be saved in a lossless format so it stays crisp → school_logo.png
Q4
Music for a phone is often saved in a lossy format so the song takes up far less storage → song.mp3
Q5
Save the school logo as JPEG because JPEG is lossless → JPEG is lossy, not lossless. It can blur the sharp edges of a logo, so PNG is the better choice.
Q6
movie.mp4 can be restored exactly to the original video → MP4 video is lossy, so the discarded data cannot be restored. Only lossless formats like ZIP or FLAC restore the original.
Section C: Definitions
Q1
Compressed file format — A file type that stores data compressed: ZIP, PNG, FLAC are lossless; JPEG, MP3, MP4 are lossy. Each suits its content, such as photos, logos, music, video or documents.Section D: Fill in the Blanks
Q1
photoFormat = "JPEG"
compression = "lossy"Q2
logoFormat = "PNG"
compression = "lossless"Q3
musicFormat = "MP3"
compression = "lossy"Q4
videoFormat = "MP4"
compression = "lossy"Q5
documentFormat = "ZIP"
compression = "lossless"Section E: Spot the Error
Q1
D — JPEG is a lossy format because it permanently throws away some detail to make photos smaller. Line 4 should print "Lossy".
Q2
A — A function definition must end with a colon. Line 1 should be def best_for_logo():
Q3
A — The file name is text, so it needs quotes. Without them Python treats song.mp3 as a variable. It should be music = "song.mp3".
Q4
B — ZIP is used for documents because it is lossless and every character must come back exactly. Line 2 should be method = "lossless".
Q5
C — MP4 video uses lossy compression to get small files that can be streamed. Line 3 should say MP4 is lossy.