Video Bit Depth Explained
Digital video data is measured in a combination of 0s and 1s 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 (color resolution), the higher the color range (number of colors 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 colors they are capable of displaying.
The number of colors is based on per channel (Red, Green, and Blue) per pixel.
So, bit depth is essentially the number of colors in a pixel.
Different Types of Video Bit Depth
An 8-bit color range is 2 to the power of 8.
In other words, the number of colors would be (2 × 2 × 2 × 2 × 2 × 2 × 2 × 2) which will give rise to 256 colors.
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 colors
24-bit color would follow the same formula and result in a16. 8 million colors.
Most of the latest monitors support 16 and 24-bit colors.
Forgotten Video Bit Depth
Here are some other (forgotten) video bit depths that have made their presence felt in the past.
2 Bit Colour (4 colors): Using the formula above the total color is 4 (2 x 2). So only four colors are seen for this color depth. The 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.
5-bit color ( 32 colors) The original Amiga chipset supported this video bit depth.
6-bit color (64 colors) This video color depth was also supported by the original Amiga chipset