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Information Communication Technology ICT
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1.
Create a table to compare and contrast the advantages and disadvantages of reducing image resolution versus reducing colour depth for file size optimization.
The following table summarizes the advantages and disadvantages of reducing image resolution and colour depth for file size optimization:
| Feature | Reducing Resolution | Reducing Colour Depth |
| Advantages | Smaller file size, faster loading times, suitable for images where detail is not critical. | Smaller file size, faster loading times, can be useful for images with limited colour palettes. |
| Disadvantages | Loss of detail, potential pixelation, may not be suitable for images requiring high quality. | Loss of colour range, potential for banding or posterization, may not be suitable for images requiring a wide range of colours. |
2.
Explain the potential benefits of adjusting the contrast of an image. Provide at least three distinct advantages, and briefly describe how adjusting the contrast can achieve each of these benefits.
Adjusting the contrast of an image offers several benefits:
- Improved Visibility of Details: Increasing contrast can make subtle details within the image more apparent. This is achieved by enhancing the difference between light and dark areas, making edges and textures stand out.
- Enhanced Visual Appeal: A well-adjusted contrast often makes an image more visually engaging and aesthetically pleasing. It can create a more dynamic and interesting look.
- Better Readability (for text or graphics): When an image contains text or graphics, increasing the contrast can improve readability. This is because it separates the foreground elements from the background more effectively.
- Correcting for Poor Lighting: Images taken in low light conditions often have poor contrast. Adjusting the contrast can help to compensate for this, making the image more usable.
3.
Describe the steps a user might take in a typical image editing software (e.g., Photoshop, GIMP) to increase the contrast of an image. Include specific terminology related to the software interface (e.g., sliders, curves, histogram). Assume the user is starting with an image that has low contrast.
Here's a typical workflow for increasing image contrast in image editing software:
- Open the Image: First, open the image in the image editing software.
- Access the Contrast Adjustment Tool: Locate the contrast adjustment tool. This is usually found in the 'Image' menu, often under 'Adjustments' or 'Tone Balance'. It might be labelled as 'Contrast', 'Levels', or 'Curves'.
- Using the Contrast Slider: Many programs provide a simple contrast slider. Dragging this slider to the right will increase the contrast, making the light areas brighter and the dark areas darker. Observe the image as you adjust the slider.
- Using Levels (more control): The 'Levels' adjustment provides more precise control. It displays a histogram representing the tonal range of the image. By dragging the black, grey, and white input sliders, you can adjust the tonal range and increase contrast. Moving the black slider to the right darkens the shadows, the white slider lightens the highlights, and the grey slider adjusts the midtones.
- Using Curves (most control): The 'Curves' adjustment offers the most control. It allows you to manipulate the tonal range by drawing a curve on a graph. Pulling the curve upwards increases contrast, while pulling it downwards decreases contrast. This is a more advanced technique but provides the greatest flexibility.
- Review and Fine-tune: After making adjustments, carefully review the image to ensure the contrast is appropriate and doesn't introduce unwanted artifacts (e.g., clipping of highlights or shadows). Fine-tune the settings as needed.