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Unit notes and practice questions

Grade 9 Information Technology unit 4: Image processing and multimedia

Everything here is for unit 4 of the Grade 9 Information Technology textbook: what the chapter covers, the short notes, practice questions with their answers, and the lesson video where one exists.

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4
Cards
10
Practice questions on unit 4
145–191
The textbook pages for unit 4

What unit 4 covers

  1. 1.Image
  2. 2.Multimedia Production Planning Strategies
  3. 3.Using Image Processing Software
  4. 4.Unit Review Exercise

Short notes for unit 4

The cards filed under this chapter on the Grade 9 Information Technology page. Open one at a time.

DefectUnderlying CauseCorrection Method in Photoshop
Red EyeCamera flash positioned right above lensRed Eye Tool under Healing Brush
Hot SpotFlash reflecting on shiny skin or surfacesClone Stamp Tool set to Darken blend mode
UnderexposureShooting indoors without flashDuplicate layer (Ctrl + J) and adjust Exposure
Dull ColorsMuted or low color intensityHue/Saturation adjustment layer

When you use it

Use when diagnosing photographic defects caused by lighting or camera flash and selecting their fix.

Watch out

When using Clone Stamp for hot spots, you must change the Blend Mode from Normal to Darken so only pixels lighter than the sample point are replaced.

Drafted from Grade 9 Information Technology, pages 145-191, then checked twice before it went up

When you use it

Reference when manipulating black, grey, or white sliders in a Levels adjustment layer.

Watch out

Dragging the black or white slider past the edges of the histogram data causes clipping. This permanently destroys tonal details in shadows or highlights.

Drafted from Grade 9 Information Technology, pages 145-191, then checked twice before it went up

Sharpening MethodCore SettingsOperating Principle
Unsharp MaskAmount, Radius (0.3 to 0.5), ThresholdSubtracts a blurry mask to detect edges, then increases edge contrast
Smart SharpenAmount (start 150%), Radius (1 to 2)Enhances edge sharpness with built-in Noise Reduction controls
High Pass FilterRadius (2 to 5), Blend Mode (Overlay, Soft Light)Extracts edges onto a gray layer and blends contrast into the original

When you use it

Select when choosing an appropriate sharpening technique to enhance image edge definition and clarity.

Watch out

High Pass filter requires converting the layer into a Smart Object first to keep the sharpening non-destructive and editable.

Drafted from Grade 9 Information Technology, pages 145-191, then checked twice before it went up

CategoryToolsPrimary Function
SelectionMove, Lasso, Object SelectionSelects, isolates, and moves objects or layers
Crop and SliceCrop Tool, SliceCuts out and removes unwanted outer areas
RetouchingSpot Healing Brush, Clone StampRemoves blemishes and samples pixels across areas
PaintingBrush, Gradient, EraserApplies strokes, color transitions, or deletes pixels
NavigationHand, ZoomNavigates view and magnifies specific pixel areas

When you use it

Consult when identifying the proper image editing tool category and its dedicated purpose.

Watch out

The toolbar displays single tools by default. Right click or click the small arrow on a tool icon to access hidden sub-tools.

Drafted from Grade 9 Information Technology, pages 145-191, then checked twice before it went up

Practice questions on unit 4

10 multiple-choice questions written against this chapter, each with its answer and the reason. Try one before you open the answer.

Question 1

What is the smallest element of a digital image?

  1. A.Pixel
  2. B.Layer
  3. C.Ruler
  4. D.Canvas
Show the answer and why

Answer: A Pixel

Why

A digital image is made up of combinations of binary digits or pixels. A pixel is the smallest element of an image.

Question 2

In digital image processing, what does the abbreviation PPI stand for?

  1. A.Point Presentation Interface
  2. B.Pixel Per Inch
  3. C.Picture Process Index
  4. D.Program Pixel Input
Show the answer and why

Answer: B Pixel Per Inch

Why

Image resolution is described in PPI, which stands for Pixel Per Inch. It measures how many pixels appear in one inch of an image.

Question 3

Which image editing technique is defined as removing portions of a photo to create focus or strengthen the composition?

  1. A.Sharpening
  2. B.Cropping
  3. C.Saturation
  4. D.Blurring
Show the answer and why

Answer: B Cropping

Why

Cropping is the process of cutting out or removing unwanted outer parts of a photo to focus on a specific area.

Question 4

Which keyboard shortcut is used to duplicate a layer in Adobe Photoshop?

  1. A.Ctrl + J
  2. B.Ctrl + D
  3. C.Ctrl + N
  4. D.Ctrl + T
Show the answer and why

Answer: A Ctrl + J

Why

Pressing Ctrl + J on the keyboard quickly duplicates the selected layer in Photoshop.

Question 5

According to the textbook, which medium was the first mass communication medium to communicate ideas using text, graphics, and images?

  1. A.Radio
  2. B.Television
  3. C.Newspapers
  4. D.Cinema
Show the answer and why

Answer: C Newspapers

Why

The use of multimedia began with newspapers, which served as the first mass communication medium combining text, graphics, and images.

Question 6

A student in Addis Ababa is planning a video project scene by scene. Which planning strategy uses a sequence of sketches and illustrations to tell a story visually?

  1. A.Storyboard
  2. B.Histogram
  3. C.Color wheel
  4. D.Unsharp mask
Show the answer and why

Answer: A Storyboard

Why

A storyboard is a graphic layout that sequences illustrations and images to plan out the flow of a multimedia product scene by scene.

Question 7

Which Photoshop retouching tool is used to sample pixels from one area of an image and paint them over pixels in another area?

  1. A.History Brush Tool
  2. B.Clone Stamp Tool
  3. C.Blur Tool
  4. D.Dodge Tool
Show the answer and why

Answer: B Clone Stamp Tool

Why

The Clone Stamp Tool is a basic retouching tool that copies (samples) pixels from a chosen point and paints them into another location.

Question 8

What happens to a colored photograph if its saturation is completely removed using an adjustment layer?

  1. A.It turns into a black-and-white or grayscale image.
  2. B.It changes into a bright solid red color.
  3. C.It deletes the background layer completely.
  4. D.It inverts all highlights into dark shadows.
Show the answer and why

Answer: A It turns into a black-and-white or grayscale image.

Why

Saturation controls color intensity. Reducing saturation completely removes all color tones, leaving only a grayscale or black-and-white image.

Question 9

When removing a shiny hot spot from a photo using the Clone Stamp Tool, which Blend Mode is chosen so that only lighter pixels are changed?

  1. A.Multiply
  2. B.Darken
  3. C.Screen
  4. D.Dissolve
Show the answer and why

Answer: B Darken

Why

Setting the Blend Mode to Darken ensures that Photoshop only replaces pixels that are lighter than the sampled reference point, effectively toning down shiny hot spots.

Question 10

When sharpening an image with the High Pass filter in Photoshop, which two contrast-boosting blend modes are most commonly used?

  1. A.Overlay and Soft Light
  2. B.Multiply and Screen
  3. C.Color Burn and Darken
  4. D.Difference and Exclusion
Show the answer and why

Answer: A Overlay and Soft Light

Why

Overlay gives higher contrast for stronger sharpening, while Soft Light provides lower contrast for subtle sharpening.

The app holds 12 questions on this unit, marked as you go. These are the first 10.

The textbook pages for unit 4

Unit 4 runs from page 145 to page 191 of the Ministry of Education edition.

Ministry of Education edition, English, 251 pages

Download the PDF

All Grade 9 Information Technology short notes

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