Bit Depth.

Bit Depth:

The colour information stored in an image is known as "Bit Depth", within bit depth, the higher the bit depth of an image the more colour it can store. Simple images, which can be a 1 bit image, can only store two colours which are black and white. However, an 8 bit image can store 256 possible colours, while a 24 bit image can display around 16 million colours. Within bit depth, is bit “monochrome” which can also be known as a “binary image”. In a binary image, only two colours can represent each pixel, these colours are, black and white. However, only some pieces of hardware can handle images that are binary for example, laser printers, fax machines etc. These binary images are usually small files and are mostly stored in the bitmap format. In addition to this, high colour graphics is also a method involved within bit depth. High colour graphics is a method which involves image information, which is stored so that every single pixel is represented by two bytes. Usually, the colour will be represented using all of the 16 bytes however, some systems will support 15 bytes. 15 bit high colour allows for 32’768 possible colours. In 16 bit, the green component is usually selected for the extra bit, this is because the users eye is more sensitive to green shades rather than red or blue shades. 16 bit will  also provide 65, 536 colour options. True colour, usually involves around 256 shades of red, green and blue, this then provides a total of at least 16, 777, 216 coloured type variations, each individual pixel has one byte which is used for each channel. Systems with more than 8 bits per channel are usually referred to as true colour.  Along with this, sampling in bit depth also occurs. The higher the sample rates, the greater the accuracy, which then gives a better digital representation to the users eye.

  

 Image source: https://documentation.apple.com/en/finalcutpro/usermanual/Art/L01/L0108_BitGraph.png