Digital Images

Suitable for students of computing and digital media in secondary school, this in-depth reference resource covers many aspects of image data storage and compression.

A brief introduction includes how images are perceived by the human eye and how they are captured and stored by digital devices. Also:

• Colour depth is explained in terms of the bits required to store colour images, and the effect on image quality is discussed.
• The use of hexadecimal codes for RGB colour values is also included, as are monochrome and binary images.
• Transparency and alpha planes are explained.
• Techniques for reducing image file size are covered in detail, such as the use of colour palettes. Various compression methods such as run-length data compression and the algorithms associated with PNG and JPEG files are illustrated.
• The difference between lossy and lossless compression is highlighted.
• The common image formats are then compared, including GIF, JPEG, PNG, TIFF and BMP.