2. Starter Activity: ASCII Art
Go to: http://www.glassgiant.com/ascii/
Convert a picture of your choose to ASCII text art -
a jumble of letters, numbers and symbols that do
not appear to have any significance until you step
back and look at the whole picture.
Sounds and Images
3. In this lesson you will learn about how computers
create sounds and images. You converting binary
numbers into images, explore how colours are
created and how a computer produces sound.
Lesson
Objectives
Understand how a computer creates images
Be able to convert binary into an image and visa versa
Understand how different colours are created
Understand how a computer produces sounds
Sounds and Images
4. Images
•A computer monitor is made up of lots of dots
called pixels arranged in rows and columns
•Each pixel displays some combination of red,
green or blue
Sounds and Images
5. Binary to Pixels
The interface between you computer and monitor
translates binary-coded information into the colour
combinations that make up an image.
Sounds and Images
6. Task 5: Binary to Image Conversion
Click on the link named ‘Binary to Image’ which is
in the Getting Technical folder in Groupwork. Click
on the squares with a “1” in them to turn them on.
Be ready for a small surprise!
Sounds and Images
7. Task 6: Image to Binary Conversion
Open the file named ‘Image to Binary’ which is in
the Getting Technical folder in Groupwork. Create
two (black and white) images as shown in the
example below and then convert each image into
binary.
Sounds and Images
8. Colour Depth/Bit Depth
The more bits per pixel the greater combination of
binary numbers and therefore colours.
Sounds and Images
8 bit 2 bit 1 bit
9. Task 7: Bit Depth
Open the image named ‘Mr Winrow’ in Serif
DrawPlus. It is saved in the Getting Technical folder
in Groupwork.
1.Click on File > Export > Export as Image
2.Change the Format from JPG to BMP
3.Check out what the image would look like if you
exported it with different Bit Depths
4.Notice how when the image quality/bit depth is
reduce the file size of the image also reduces
Sounds and Images
10. Colours as Numbers
•Colours are made by mixing red, green and blue
•If 8 bit numbers are used values can range from
0 – 255 for each of the colours
•Black would be represented by (R=0, G=0, B=0)
•Red (255, 0, 0), Green (0, 255, 0), Blue (0, 0, 255)
•A pale yellow colour would be (200, 180, 120)
•Colours on the Internet can also be represented in
hexadecimal codes – Remember #000000
Sounds and Images
11. Sounds
Analogue information that we can hear cannot be
understood by a computer it needs to be
converted into digital information.
Sounds and Images
12. Sounds Cards
Sound cards convert digital information (binary) to
analogue sounds that we can hear. If a
microphone is plugged into a sound card they can
also convert analogue sounds to digital
information.
Sounds and Images
13. Sounds Cards
The more information that is recorded about each
point in a sound or music track the better quality
the recording will be.
Sounds and Images
14. Task 8: Sound Quality
Listen carefully to the next 4 sound tracks. Arrange
them in order from the worst to the best quality.
Sounds and Images
Track Number Sound Quality
Worst
Best
15. Task 8: Sound Quality - Answers
Listen carefully to the next 4 sound tracks. Arrange
them in order from the worst to the best quality.
Sounds and Images
Track Number Sound Quality
Task D
Task A
Task B
Task C
Worst
Best
16. Plenary: 5 Key Points
Note down five key points which summarise what
you have learnt in today’s lesson. Be ready to
share your points with the rest of the class.
Sounds and Images
17. Keywords
Understand how a computer creates images
Be able to convert binary into an image and visa versa
Understand how different colours are created
Understand how a computer produces sounds
Objectives
Pixels
Monitor
Binary
Bits
Colour Depth
Hexadecimal
Analogue
Modem
Sounds and Images
