Computer Science – Text, sound and images | e-Consult

The number of pixels in the image is calculated by multiplying the width by the height: 1280 pixels * 720 pixels = 921,600 pixels.

Images can be compressed to reduce file size using various methods, broadly categorised as lossy and lossless compression. Lossy compression (e.g., JPEG) achieves smaller file sizes by discarding some image data. This can result in a slight reduction in image quality, but the reduction is often imperceptible, especially at higher compression levels. Lossless compression (e.g., PNG) reduces file size without losing any image data. This means the original image can be perfectly reconstructed from the compressed file.

There is a trade-off between file size and image quality. Lossy compression offers significantly smaller file sizes but at the cost of some image detail. Lossless compression preserves all image detail but results in larger file sizes. The choice of compression method depends on the application. For example, photographs might benefit from lossy compression to reduce file size, while images with sharp lines and text (like diagrams or logos) might be better suited to lossless compression to avoid artefacts.