Pixel Representation

Let us study some basic terms before starting with programs.

1) Pixel :- 

Its is a smallest unit of a picture that can be represented.The address of a pixel corresponds to its coordinates. Pixels are normally arranged in a two-dimensional grid, and are often represented using dots or squares.
In color image pixels are normally represented in RGB or CYMB. Major image file formats are JPEG, EXIF, TIFF, RAW, PNG, GIF, BMP etc. They can also be represented as vector formats like CGM, SVG etc. Pixel in a modern computer image is represented by four unsigned 8-bit bytes of data.  Three of those four bytes represent the colors red, green, and blue.  The fourth byte, often referred to as the alpha byte, represents transparency. In black and white image, black has the value 0 and white 255.  If the value is 0, the pixel is completely transparent regardless of the values of the color bytes.  If the value is 255, the pixel is completely opaque with the color of the pixel being determined exclusively by the values stored in the three color bytes

2) Pixel Representation :-

Alpha
Red
Green
Blue

 MSB                                                                                                            LSB


3) Pixel Density or Pixel Per Inch (PPI) :-

It is a measurement of the resolution of devices in various contexts like image scanners, digital cameras, monitors etc

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