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What are Pixels?
Pixel stands for "Picture Element". It is the smallest unit of information in a digital image. These pixels are arranged
in a 2-dimensional grid to form a complete image, video, text, or any visible thing on a digital platform. A pixel
can have only one color at a time. Colour of a pixel is determined by the number of bits it represents. The more
pixels you have, the more closely the image resembles the original.
Resolution is basically the dimensions through which you can measure how many pixels are on a screen. Today’s
screen displays typically offer resolution consisting of millions of pixels or megapixels. Screen resolution is
calculated by displaying the numbers of pixels displayed vertically or with the number of pixels displayed
horizontally. For example, a full HD screen displays a popular HD of 1080p, which means 1080 Pixels tall by
1920 pixels wide.
A single static image on a full HD screen displays 2 megapixels. 1080 X 1920 = 2,073,600 (2 megapixels). But full
motion video refreshes the screen many times per second to depict motion.
Every image that is represented in the form of pixels also describes other features like brightness and color code.
The most common pixel format is Byte Image, where the number is stored in an 8-bit integer ranging between
0–255, where 0 means No Color/Black and 255 represents Full Color / White.
Basics of Images
An image is a visual representation of any object. The term ‘image’ means a picture that has been created or stored
in electronic form. It can be described in terms of vector graphics or raster graphics. An image comprises of a
rectangular array of dots known as pixel. The size of the image is specified as width*height, in the number if pixels.
There are different types of images let us study about them in detail.
Greyscale Images
A grayscale image is the one in which the value of each pixel is
single, i.e., it carries only intensity information. Also known as
Black and White, it has shades of grey. RGB channels of pixels have
the same value. These are images with only 2 colors, black and
white, varying from black at the weakest intensity to white at the
strongest. A grayscale image has each pixel of size 1 byte having a
single plane of 2D array of pixels. In grayscale images, the shades
range starts with 0 and ends with 255, i.e., it starts with pure black
and ends with pure white.
RGB Images
R B All colored images around us are made up of 3 primary colors of Red, Green and
Blue. All the colors are made by mixing the 3 basic colors of the RGB in varying
intensity. Every colored image when split is stored in the form of 3 different
channels, R Channel, G Channel and B Channel. Each channel has a pixel value
G varying from 0-255. For example, if we see the turquoise color RGB band would
look like [64, 224, 208]. In a colored image a single pixel contains red, green and
blue values in triplets.
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