Image resolution

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Quick Questions

Shade in the A or B circle for each question.

1. Which answer describes image resolution?

A The number of pixels in an image, given as width x height

B The number of colours in a rainbow

2. An image is 1920 x 1080. What do these numbers mean?

A 1920 colours and 1080 shades

B 1920 pixels wide and 1080 pixels high

3. What happens when you zoom in very close on a digital image?

A You can see the individual square pixels

B The image turns back into a real photo

4. Which image has the higher resolution?

A 640 x 480

B 1920 x 1080

5. What do more pixels in an image usually give you?

A More detail, but a bigger file

B Less detail and a smaller file

Match the Pairs

Draw a line connecting each item on the left to its match on the right.

Left column		Right column
11920 x 1080		AResolution is counted in pixels (width x height), not in centimetres. Centimetres measure physical size.
2resolution		BThe number of pixels in an image, given as width by height
3Zooming in on a digital image far enough shows the individual square pixels it is made of		CA resolution of 1920 pixels wide and 1080 pixels high, which is about 2 million pixels in total
4An image with more pixels has a higher resolution, so it shows more detail but uses a bigger file		D640 x 480 has fewer pixels than 1920 x 1080, so it has less detail, not more.
5Resolution is the screen size in centimetres		E1920 x 1080 > 640 x 480
6640 x 480 has more detail than 1920 x 1080		Fzoom in -> see pixels

Definitions

resolution

Fill in the Blanks

Complete each line of code by filling in the missing parts.

# 1920 pixels wide, 1080 pixels high __________ = 1920 x 1080

width = 1920 height = 1080 pixels = width _ height

IF pixelsA _ pixelsB THEN detail = "higher" END IF

# Zoom in to see the pixels view = ____(photo, 800)

width = 1920 height = 1080 resolution = _____ x height

Spot the Error

Shade in the letter of the line that contains an error.

Question 1

A width ← 1920

B height ← 1080

C pixels ← width * height

D OUTPUT pixel

Question 2

A zoom ← 10

B IF zoom > 8

C OUTPUT "You can see pixels"

D END IF

Question 3

A width ← 1920

B height ← 1080

C pixels ← width + height

D OUTPUT pixels

Question 4

A small ← 640 * 480

B large ← 1920 * 1080

C IF large < small THEN

D OUTPUT "More detail"

E END IF

Question 5

A resolution ← 1920 x 1080

B pixels ← 1920 * 1080

C OUTPUT resolution

Answer Key

Image resolution

Section A: Quick Questions

A — The number of pixels in an image, given as width x height

B — 1920 pixels wide and 1080 pixels high

A — You can see the individual square pixels

B — 1920 x 1080

A — More detail, but a bigger file

Section B: Match the Pairs

1920 x 1080 → A resolution of 1920 pixels wide and 1080 pixels high, which is about 2 million pixels in total

resolution → The number of pixels in an image, given as width by height

Zooming in on a digital image far enough shows the individual square pixels it is made of → zoom in -> see pixels

An image with more pixels has a higher resolution, so it shows more detail but uses a bigger file → 1920 x 1080 > 640 x 480

Resolution is the screen size in centimetres → Resolution is counted in pixels (width x height), not in centimetres. Centimetres measure physical size.

640 x 480 has more detail than 1920 x 1080 → 640 x 480 has fewer pixels than 1920 x 1080, so it has less detail, not more.

Section C: Definitions

resolution — The number of pixels in an image, given as width x height (like 1920 x 1080). More pixels give more detail but make a bigger file.

Section D: Fill in the Blanks

# 1920 pixels wide, 1080 pixels high
resolution = 1920 x 1080

width = 1920
height = 1080
pixels = width * height

IF pixelsA > pixelsB THEN
  detail = "higher"
END IF

# Zoom in to see the pixels
view = zoom(photo, 800)

width = 1920
height = 1080
resolution = width x height

Section E: Spot the Error

D — The variable is called pixels, not pixel. The program has no variable named pixel, so it should say OUTPUT pixels.

B — An IF line needs THEN at the end. It should be IF zoom > 8 THEN.

C — The number of pixels in an image is the width multiplied by the height, not added. It should be pixels ← width * height.

C — The larger resolution has more pixels, so large > small is true and gives more detail. The < sign is the wrong way round. It should be IF large > small THEN.

A — The resolution is written as text, so it needs quotes. It should be resolution ← "1920 x 1080".