Working with images Cambridge IGCSE Information & Communication Technology revision
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In plain words
An image dropped into a document is rarely right first time. It is too big, or shows too much, or faces the wrong way. A handful of tools fix all of that, and the examiners look hardest at one thing: have you distorted it?
6 things to know
- Resizing changes the size of an image. Keeping the aspect ratio, the ratio of width to height, stops the image looking stretched or squashed.
- Cropping removes unwanted parts from the edges of an image.
- Rotating turns an image through an angle. Reflecting (flipping) makes a mirror image, horizontally or vertically.
- Brightness makes the whole image lighter or darker. Contrast changes the difference between the light and dark areas.
- Images can be layered, by sending one behind or bringing it in front of another, and grouped, so that several move and resize as one.
- The file size of an image can be reduced by lowering its resolution, which is the number of pixels, or its colour depth, which is the number of colours. Both lower the quality.
Worked example
A photo 800 pixels wide and 600 pixels high must be made 400 pixels wide without distortion. What height is needed?
- The aspect ratio must stay the same. The width has been halved.
- So the height must be halved too: 300 pixels.
Tips and tricks
- "Maintain the aspect ratio" is the phrase for resizing without distortion.
- Cropping cuts parts away. Resizing keeps the whole image and changes its size. Do not use one word for the other.
It lands in your notebook with its questions as flashcards.
Working with images: 5 questions and answers
These are the quiz’s questions. Do the quiz first, then come back here for the ones that got you.
What does cropping an image do?
Only part of the picture is kept.
What must be kept the same to avoid distorting an image when it is resized?
The width and height change by the same proportion.
What does reflecting an image do?
It can be flipped horizontally or vertically.
An image is 600 pixels wide and 400 high. It is resized to 300 wide with the aspect ratio kept. What is its height?
Both dimensions are halved.
What is the effect of reducing the resolution of an image?
There are fewer pixels to store.
Quiz
5 questions
Tap an answer and you’ll see straight away whether it’s right, and why.
Worksheet
2 questions, 4 marks. Write your answers on paper, then check them.
Working with images
Cambridge IGCSE Information & Communication Technology 0417 · 4 marks · papermunch.org
Name ______________________________ Date ______________
Describe the difference between cropping and resizing an image.[2]
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Cropping removes parts of the image from its edges. Resizing changes the size of the whole image without removing any of it.
State two ways of reducing the file size of an image.[2]
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Reduce the resolution of the image. Reduce the colour depth of the image.
Answers: Working with images
- 1. Cropping removes parts of the image from its edges. Resizing changes the size of the whole image without removing any of it.
- 2. Reduce the resolution of the image. Reduce the colour depth of the image.