Which image file format is commonly used for digital photography and uses lossy compression?

Which image file format is commonly used for digital photography and uses lossy compression?

• A. PNG-24
• B. PNG-8
• C. GIF
• D. JPEG

Answer: (D)

JPEG is the format designed for digital photography because it uses lossy compression to shrink file sizes while preserving natural-looking color and detail. In this approach, information is selectively discarded during compression (through processes like discrete cosine transform, quantization, and chrominance subsampling), which significantly reduces the amount of data needed to represent the image. The result is much smaller file sizes that are ideal for storing, sharing, and viewing photos across devices and the web, with quality tuned by choosing a compression level. PNG, by contrast, is lossless, meaning no data is discarded and files stay large; PNG-8 also limits color to 256 colors, which worsens photo fidelity. GIF uses a different, lossless compression method but is restricted to 256 colors and is mainly intended for simple graphics or animations, not high-quality photographs. These differences make JPEG the go-to choice for digital photography when lossy compression is desired.

JPEG is the format designed for digital photography because it uses lossy compression to shrink file sizes while preserving natural-looking color and detail. In this approach, information is selectively discarded during compression (through processes like discrete cosine transform, quantization, and chrominance subsampling), which significantly reduces the amount of data needed to represent the image. The result is much smaller file sizes that are ideal for storing, sharing, and viewing photos across devices and the web, with quality tuned by choosing a compression level.

PNG, by contrast, is lossless, meaning no data is discarded and files stay large; PNG-8 also limits color to 256 colors, which worsens photo fidelity. GIF uses a different, lossless compression method but is restricted to 256 colors and is mainly intended for simple graphics or animations, not high-quality photographs. These differences make JPEG the go-to choice for digital photography when lossy compression is desired.