Aspect ratio — scale width and height by the same factor to keep it
Aspect ratio is the ratio of an image's width to its height (e.g. 4:3 or 16:9). To resize while MAINTAINING it, both width and height must be scaled by the SAME factor, or the image is stretched or squashed. A lock aspect ratio option recalculates the second dimension automatically. Worked proportion: a 1600 x 1200 pixel image resized to 800 pixels wide keeps its ratio when the new height is pixels — both scaled by one half.
Each editing operation does a different thing
These are NOT interchangeable. Crop removes the outer parts, keeping only a selected rectangle. Rotate turns the whole image about a point by an angle. Reflect / flip mirrors it horizontally or vertically. Brightness is overall lightness; contrast is the gap between the lightest and darkest areas. Group combines objects to move or resize together as one unit; layer order (move to front / back) sets which overlapping image is drawn on top.
File size — reduce resolution or colour depth, and both cost quality
File size depends on how much data the image stores. Reduce the resolution — fewer pixels, so less data, but the image looks less sharp. Reduce the colour depth — fewer colours per pixel, which can cause banding or loss of subtle shading. Both make the file smaller and faster to send, but both lower quality. The right choice depends on PURPOSE: a web thumbnail tolerates a low-resolution file, but a printed photo needs full resolution and colour depth kept.
Drawn from real examiner reports.
Crop ≠ resize (remove vs keep whole)
Crop permanently removes the unwanted outer parts of an image, keeping only a selected rectangular region — what the image shows is reduced. Resize keeps the WHOLE image but only changes its overall dimensions; nothing is discarded. When a question asks to remove an unwanted background, use crop, not resize — shrinking with resize keeps the background, just smaller.
Maintain ≠ adjust the aspect ratio
To MAINTAIN the aspect ratio, both width and height are scaled by the same factor. Typing only one new dimension with the aspect-ratio lock OFF changes just that dimension, so the image is stretched or squashed — the ratio has been ADJUSTED, not maintained. Drag a corner handle (not an edge handle), or turn the lock on so the second dimension recalculates automatically.
Alt text too brief for a screen reader
Alt text is a description attached to an image so a screen reader can read it aloud, or text shows in its place, if the image fails to load. A one- or two-word alt text such as "photo" or "car" is not enough — it must describe what the image actually shows (e.g. "a red sports car crossing the finish line"). Leaving it empty or copying the filename also fails.
w23 P03 Q3: alt text must be detailed enough for a screen reader to convey what the image is if it fails to load.
Width: inline style, not an HTML attribute
Set an image's width with an inline style attribute — style="width:100%" — not an HTML width attribute; modern practice separates content from presentation. A further trap: an img tag must carry only ONE width specification. Putting both an HTML width attribute AND an inline style="width:…" on the same tag is contradictory and does not evidence the required method.
w23 P03 Q3: use an inline style attribute (style="width:100%") not an HTML width attribute, and only one width attribute per img tag.
Name the action, not the brand of software
When describing how to edit an image, describe the generic action — "load image-editing software, then select and crop the required area" — never a specific brand or proprietary product; examiners give no credit for brand/trade names anywhere in ICT. Vague answers score no better: "edit the photo" without naming the operation (crop / resize / rotate) fails to show the method.
s22 P11 Q11: editing an image = load editing software, crop; no proprietary software names credited.
Group ≠ layer order (front/back)
Grouping combines several images or objects so they can be moved, resized or rotated together as one unit (ungroup splits them again). Layer order (move to front / move to back) only controls which of two OVERLAPPING images is drawn on top. Grouping does not by itself change which image appears in front, and changing layer order does not combine the images.
Resolution ≠ colour depth
Reducing the file size has two separate methods that are easy to confuse. Resolution is the number of pixels in the image; colour depth is the number of colours available per pixel. Lowering either reduces the data stored, but they are not the same control — and assuming only one method exists is wrong; a question may ask for both, each with its own effect on quality.
Describe the operation in sequence, in generic terms
For a "describe how to…" image question, state the steps in order using generic terms — "load image-editing software; select the required area; crop to remove the background; resize with the aspect ratio locked to fit". Never a brand name, and never just "edit the image".
Justify size/quality choices against the purpose
If asked to justify reducing resolution or colour depth, link the choice to the scenario: "reduce the resolution because the image is a web thumbnail" (small display, faster to load), not a vague "to save space". Tie every quality trade-off to how the image will actually be used.
Check: both dimensions, or just one?
"Maintain the aspect ratio" needs BOTH dimensions scaled by the same factor; "adjust the aspect ratio" is a deliberate stretch or squash. Read which the question asks for before you resize, and for a proportion calculation scale by the same factor rather than dividing.
Edit before you shrink the file
Do positioning, cropping and resizing BEFORE the final resolution or colour-depth reduction. Editing an already-shrunk image loses even more quality, and re-enlarging a low-resolution image cannot restore the detail that has already been discarded.
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