Video Bit Depth Explained

Digital video data is measured in a combination of 0 and 1 called bits (binary digits).
Video bit depth refers to the number of bits per pixel of video.

The word pixel, for your information, is derived from (picture (pix) and element (el) or picture cell).

In digital video its composition is measured in bits and the space it takes up is measured in bytes.

A bit takes up 0.125 bytes of storage space.

So, 8 bits make up a byte.

To recap, the more the bits in a pixel of video image, the higher the bit depth (colour resolution), the higher the colour range (number of colours displayed) and the bigger the space it takes up.

That said, here are the different types of video bit depth commonly encountered and the number of colours they are capable of displaying.

The number of colors are based on per channel (Red, Green and Blue) per pixel.

Different Types of Video Bit Depth

An 8 bit colour range is 2 to the power of 8.

In other words, he number of colours would be (2 × 2 × 2 × 2 × 2 × 2 × 2 × 2) which will give rise to 256 colours.

16 bit colour would be (2 × 2 × 2 × 2 × 2 × 2 × 2 × 2 x2 × 2 × 2 × 2 × 2 × 2 × 2 × 2)
That would be 65, 536 colours

24 bit colour would follow the same formula and result in a16. 8 million colours.

Most of the latest monitors support 16 and 24-bit colour.

Video Color Depth Number of Colors

Forgotten Video Bit Depth

Here are some other (forgotten) video colour depths that have made their presence felt in the past.

2 Bit Colour (4 colors) : Using the formula above the total colour is 4 (2 x 2) . So only four colours are seen for this color depth. 2 bit color was seen in early CGA monitors like NeXTstation Macintosh monitors and also Atari ST.

3-Bit Colour ( 8 colors) : It was seen in earlier home computers like ZX Spectrum and BBC Micro which supported TV displays.

4-bit color (16 colors): Popularly referred to as EGA used in Atari ST, Commodore 64 and Amstrad CPC.

4-Bit Color depth in Commodre 64

5-bit color ( 32 colors) The original Amiga chipset supported this video bit depth.

6-bit color (64 colors) This video colour depth was also supported by the original Amiga chipset