Cambridge A Level Information Technology (ICT): Graphics creation (9626) – Revision Notes

For full explanations and worked examples, use the Graphics creation study guide. These notes condense topic 19, Graphics creation, of Cambridge International AS & A Level Information Technology (9626), following the syllabus for examination in 2025, 2026 and 2027 (version 3), sections 19.1 to 19.5. It is an A Level only topic. Paper 3 (Advanced Theory) questions are based on sections 12–21 and Paper 4 (Advanced Practical) tasks on sections 17–21, so revise both the reasons behind each tool and the skills themselves.

Links: course hub, course checklist, Graphics creation practice questions, free 10-minute diagnostics.

Topic 19 at a glance

• 19.1 Common graphics skills – layers; transform; grouping and combining; alignment, distribution and order; layout aids; colour picker; crop; colour systems; resolution; file formats and export; solid and gradient fills.
• 19.2 Vector graphics – drawing and shape tools; selection (convert to curves, replication, transformation); fills; node and path editing; tracing bitmaps and its pros and cons.
• 19.3 Bitmap images – selection and masking; colour adjustments; brushes, pencils and pens; filters; resizing image or canvas, colour depth, resolution.
• 19.4 Compression – what it is; lossless and lossy; effects on images.
• 19.5 Text – font face, size, kerning, letter spacing, line spacing; text on a path; text in a shape; text to curves.

Every design choice should be justified by the intended application and audience.

Bitmap v vector

	Bitmap	Vector
Stored as	Grid of pixels, each with a colour	Paths of nodes and curves, with stroke and fill
Enlarging	Pixelates	Stays sharp
Best for	Photographs, fine shading	Logos, icons, diagrams, text
File size depends on	Pixel count and colour depth	Number of objects and nodes
Formats	BMP, JPG, PNG, GIF, TIF	SVG (PDF can hold both)

Layer and object tools (19.1)

• Layers: add, remove, select active layer, order, toggle visibility, lock, opacity/transparency.
• Blend = how a layer combines with those below. Merge = combine chosen layers. Flatten = combine all layers into one.
• Transform: move, resize, scale, rotate, reflect, skew, shear, envelope, perspective.
• Group keeps objects separate but moving together; combine/join makes one object or joins end nodes.
• Add (union) merges outlines; subtract cuts one shape from another; intersect keeps only the overlap.
• Align edges or centres; distribute for equal spacing.
• Order: raise, lower (one step); bring to front, send to back (all the way).
• Layout: rulers, grids, guidelines, snapping for precise placement.
• Colour picker: sample a colour or colour range from the image or another source.
• Crop/clip to object: keep only what is inside a chosen shape.

Colour systems

System	Model	Components	Use
RGB	Additive (light)	Red, green, blue; all full = white	Screens, web
HSL	Rearranges RGB colours	Hue (0–360°), saturation, lightness	Intuitive colour adjustment
CMYK	Subtractive (ink)	Cyan, magenta, yellow, key (black)	Print
CMS	Colour management system	Device profiles convert colours between devices	Consistent screen-to-print colour

CMYK adds a separate black ink because mixing cyan, magenta and yellow gives a muddy dark colour rather than a true black. Some screen colours cannot be reproduced in ink, so check print work in CMYK.

Resolution

• Too low: blocky or soft images, worst in print or when enlarged.
• Too high: no visible gain on screen, but larger files, slower web pages, more storage.
• Changing colour depth: fewer bits per pixel give a smaller file but fewer colours, so smooth areas show banding.

Worked reminder. A 2000 × 1000 image with 8-bit colour: 2000 × 1000 × 8 ÷ 8 = 2,000,000 bytes = 2 MB, with 2⁸ = 256 colours.

Formulas

Quantity	Formula
Number of colours	2 to the power of colour depth (bits per pixel)
Uncompressed size (bits)	width (px) × height (px) × colour depth
Size in bytes	bits ÷ 8
Print size (inches)	pixels ÷ ppi
Pixels needed for print	inches × ppi
Effective ppi	pixels ÷ inches printed

Method in steps – is this image good enough to print?

1. Find the pixel dimensions.
2. Divide each by the print size in inches to get the effective ppi.
3. Compare with the target (high-quality print commonly targets about 300 ppi).
4. Too low: expect blocky or soft print – get a larger original or print smaller.
5. For screen use, reduce to the display size to save file size and load time.

File formats

Format	Compression	Transparency	Choose it for
SVG	Vector	Yes	Web logos and icons that must scale
BMP	Usually none	–	Simple exchange; large files
JPG/JPEG	Lossy	No	Photographs
PNG	Lossless	Yes	Logos, screenshots, sharp text
GIF	Lossless, max 256 colours	Simple	Simple graphics, short animations
TIF	Usually none or lossless	–	Print and archive masters
PDF	Mixed content	–	Fixed-layout, print-ready artwork

Paper 4: the syllabus states that work saved in an incorrect file format earns no marks for that task, so check the format every task asks for.

Vector nodes (19.2)

Node	Handles	Result
Cusp	Move independently	Sharp corner
Smooth	Kept in line	Curve passes through without a corner
Symmetrical	In line, equal length	Equal curvature both sides
Asymmetrical	In line, unequal length	Different curvature each side

• Bezier curve: shape set by end nodes and control handles (direction and strength of bend).
• Simplify a path: delete unneeded nodes; fewer nodes give a cleaner line and smaller file.
• Convert to curves: shape object becomes an editable path; shape settings lost.
• Replication: duplicates or evenly spaced copies.
• Trace bitmap: edges and colour areas become vector paths. Gains: scalable, editable, small for simple logos. Losses: detail and shading, many nodes for complex images, clean-up time.

Bitmap tools (19.3)

• Lasso (draw round), magic wand (adjacent similar colour, with tolerance), colour select (similar colour anywhere), cut-out, crop, masking (hide without deleting).
• Colour: fills; black and white (2 colours) v greyscale (shades of grey); brightness; contrast; colour balance; shadows and highlights.
• Brush/pencil/pen: pre-set or customised size, hardness, opacity, shape.
• Filters: distort, clone (cover blemishes), erase, blur, smudge, sharpen, red eye removal.
• Image resize resamples pixels; canvas resize changes the working area only.

Compression (19.4)

• Compression: reducing file size by encoding data more efficiently.
• Lossless: original rebuilt exactly; e.g. run-length encoding (RRRRBB → 4R 2B). Best on flat colour.
• Lossy: detail permanently removed; much smaller files; artefacts (blockiness, blur, banding, fuzzy edges round text); worse with each re-save.

Text (19.5)

• Kerning: space between one pair of letters.
• Letter spacing: even spacing across all selected letters.
• Line spacing: distance between lines.
• Text on a path: follows a line or wraps round a shape.
• Text in a shape: flows inside an outline.
• Text to curves: letters become paths; no font needed, letters reshaped, but no longer editable as text.

Must-know distinctions

• Additive (RGB, light, adds to white) v subtractive (CMYK, ink, absorbs light).
• Group (still separate objects) v combine/add (one object).
• Merge (some layers) v flatten (all layers).
• Magic wand (adjacent pixels) v colour select (whole image).
• Image resize v canvas resize.
• Kerning (a pair) v letter spacing (a range).
• Lossless (exact) v lossy (permanent loss).

Quick self-test

1. State how many colours a 4-bit image can show.
2. Calculate the uncompressed size in MB of a 1000 × 800 image with 16-bit colour (1 MB = 1,000,000 bytes).
3. A 1800-pixel-wide image is printed at 300 ppi. State the print width.
4. State the pixel width needed for an 8-inch-wide print at 300 ppi.
5. Write the row GGGGGYYGGGGG using run-length encoding.
6. A file shrinks from 8 MB to 0.5 MB. State the compression ratio.
7. State which colour system a commercial printer uses.
8. Give one reason to choose PNG rather than JPEG for a logo.
9. Describe a cusp node.
10. Give one disadvantage of converting text to curves.
11. Explain the difference between kerning and letter spacing.
12. Explain why a photograph should not be traced into a vector.

Answers

1. 2⁴ = 16 colours.
2. 1000 × 800 × 16 ÷ 8 = 1,600,000 bytes = 1.6 MB.
3. 1800 ÷ 300 = 6 inches.
4. 8 × 300 = 2400 pixels.
5. 5G 2Y 5G.
6. 8 ÷ 0.5 = 16:1.
7. CMYK.
8. PNG is lossless, keeping sharp edges, and supports a transparent background.
9. A node whose handles move independently, giving a sharp corner.
10. The text can no longer be edited or spell-checked as text.
11. Kerning changes the space between one pair of letters; letter spacing changes the spacing evenly across all selected letters.
12. Its shading and fine detail would be lost, and the trace would need very many nodes, giving a large, slow file.

Where marks are usually lost

• Calling CMYK additive, or saying RGB is the print system.
• Forgetting ÷ 8 when converting bits to bytes.
• Giving 2 × bit depth instead of 2 to the power of bit depth for the number of colours.
• Recommending JPEG where transparency or sharp text is needed.
• Describing tracing as “improving” a photo instead of noting the detail lost.
• Mixing up magic wand and colour select.
• Saying “text to curves makes text editable” – it does the opposite.
• Naming a file format without a reason linked to the application and audience.

Official syllabus

Cambridge International AS & A Level Information Technology 9626, syllabus for examination in 2025, 2026 and 2027, version 3, Cambridge University Press & Assessment. Topic 19: Graphics creation (19.1 Common graphics skills; 19.2 Vector graphics; 19.3 Bitmap images; 19.4 Compression; 19.5 Text).