Revision slideshow

Compression

• Lossy Compression
• some of the data is lost and cannot be recovered.
• Greatly reduces the file.
• Reduces the quality of the image/sound.
• Suitable for images,sound and video.
• Cannot be used on text and executable files.
• Lossless Compression
• None of the data is lost.It is encoded differently.
• Can be turned back into original format.
• Can be used in all types of data.
• It usually less effective than lossy compression at reducing the file size.
• Mostly suitable for documents and executable files.

Sound

• Sample size
• The total number of bits in a sound.Calculated as the bit depth multiplied by the number of samples per second, multiplied by the number of seconds.
• Bit Depth
• The number of bits stored per sample. The higher the number of the bits, the greater the quality of the sound, and the larger the file size.
• Sample frequency/rate
• The numbers of samples stored per second. The higher the number of samples per second, the higher the quality of the sound, and the larger the file size.