🎯 Learning Objectives
- Recall that bitmap images and pulse code sound are not the only binary representations of images and sound available
- Define compression, and describe why it is necessary
🥈 Level 2 – There’s always another way
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<path d="M24,38.5c5.6,0,10.3-4, ... />
<path d="M24,33.5c-3.2,0-6.1, .../>What do you think this text describes?
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C- 1 von=87 voff=0
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Cb' 65/256 von=74 voff=0How about this?
Images can be represented as sequences of colour samples, encoded in binary.
These are called bitmaps or raster images.
Sounds can be represented as sequences of sound samples, encoded in binary.
This is called pulse code modulation.
Images can be represented as collections of geometrical shapes (each with its own attributes).
These are called vector images.
Music can be represented as a sequence of musical notes (with information on how to play them).
An example is MIDI files.
Manually modify a vector image and see what happens in the Level 2 Activity.
🥉 Level 3 – Compression
Sequences of bits representing texts, images, sounds, and videos can become extremely long.
Why is this a problem?
Because more bits require more space to store, more time to transfer, and more computing power to process.
Any procedure that reduces the size of a file is called a compression method.
Use Photoshop to compress an image and examine the effect that compression has on its size.
Image for Level 3 here
🥉 Level Up
🥇 Level 1
- Complete the test given to you on Micosoft Forms by your teacher.
🥈 Level 2
- Upload your completed Level 2 – Mixed Up Emoji Word file to the Teams assignment.
🥉 Level 3
- Upload your completed Level 3 – Compression Word file to the Teams assignment.
In this lesson, you…
- Described alternative ways of representing images and sound
- Defined what compression is and why it’s necessary
In this topic, you…
- Examined how sequences of binary digits can be used to represent images and sounds
- Used software tools to manipulate images and sounds