What is a Pixel?
Pixel is the smallest unit of a digital image or a video displayed on any device. Pixel is a blend of ‘pic’ from ‘picture’ and ‘el’ from ‘voxel’. A group of pixels makes an image or a video. Pixels are also known as picture elements. They are usually represented by a square or dot on the screen. Pixel is measured in terms of display resolution. The picture quality is better when there are more pixels per inch of the display screen.
A resolution of 3840×2160 will have 8,294,400 pixels on the display screen.
Origin of the term Pixel
The term pixel was first published in the year 1965 by Fredric C Billingsley who used the term pixel to describe the picture elements in the video images of the moon and Mars space probes.
What is Bits Per Pixel (BPP)?
Most pixels consists of 8 bits that represent 256 colours.
1. A 16-bit image consists of roughly 32,000 colours. 5 bits are allocated for each red, green and blue value.
2. A 24-bit image, also known as a true image, consists of 16 million colours. 8 bits are allocated for each red, green and blue value.
3. A 32-bit image is a specialized true image with an extra byte that is either converted or ignored. This extra byte is used for additional colour.
4. 48 bit is similar to 24 bit. There are three RGB channels with 16 bits for each red, green and blue value. Each channel consists of 65,536 colours, altogether making 281.5 trillion mixed colour.
5. 64 bit is similar to 48-bits and has three colour channels with an additional channel, or the alpha channel that holds extra information.