Bitmapped Images 27 th November 2014 With Mrs Billinghurst @SGS_Computing.

Bitmapped Images

27th November 2014

With Mrs Billinghurst

@SGS_Computing

Bitmapped Images27th November 2014

Key Terms:PixelBitmapResolutionColour Depth


PixelThe smallest area of an image.

Each square in this image represents one pixel


BitmapA grid of pixels which in which the position of coloured pixels are mapped in a grid.


ResolutionThis is the number of pixels that make up an image or screen.

width x height


Colour Depth

The number of bits used to represent the colour of a single pixel in a bitmap.


Colour Depth : 1 Bit (2 colours)

White = 0Black = 1

This image is 32 pixels wide.How many bytes are needed per row? 8 bytes



White = 00Black = 01

Yellow = 10Green = 11

This image is 32 pixels wide.How many bytes are needed per row? 16 bytes



White = 000Black = 001

Yellow = 010Green = 011Brown = 100

Tan = 101Blue = 110

Light Green = 111


Also known as monochrome.

One bit is allocated to each pixel = black & white

1 Bit Colour


Each of the RGB components of a colour is given a nibble:

12 Bit Direct Colour


This simulates the colours that a human eye can see

Holding 16.7 million different colours

24 Bit True Colour


This is really just 24 bit colour with an extra 8 bits.

32 Bit Colour

Why? Modern computers work in either 32 or 64 bits (or the additional 8 bits provide transparency)





Each pixel is stored as a binary number.

OR

Each pixel is stored as a bit pattern / RGB bits


8(or 1 byte)128 64 32 16 8 4 2 1

1 1 1 1 1 1 1 1


Key Terms:PixelBitmapResolutionColour Depth

Bitmapped Images

27th November 2014

With Mrs Billinghurst

@SGS_Computing

Bitmapped Images 27 th November 2014 With Mrs Billinghurst @SGS_Computing.

Documents