30 Second Read #4 – Computer Images

Let’s examine two different types of images – bitmap (or raster) images, and vector images.

Bitmap images are made up of tiny squares of colour known as PIcture ELementS – also known as pixels.  The x made its way in there somehow. Each pixel has a binary value such as 1001 1100, which determines which colour it is.

The more binary values you can squeeze into a single pixel, then the more colours you can include in the image.  This is known as bit depth.

The resolution of an image is the number of pixels within a specified area – calculated by width x height.  So a 100 pixel wide x 100 pixel high image will have a resolution of 10,000 pixels. Standard photographs in the JPEG format are bitmap images.

 

Vector images are made in a completely different way – using mathematical algorithms which are applied to geometric shapes.  This means that they are scalable without losing any quality to the image.  If you resize a bitmap much beyond its standard size, it will deform and lose quality.  In will in fact pixelate.

If you resize a vector image, it will hold its quality.  Many clipart and emoticon images are built with vectors.

 

30 Second Read #3 – What is Hexadecimal?

Hexadecimal is a slightly bonkers numerical system, which is all the more reason to celebrate it.  Denary is in base 10, binary is in base 2, whereas hex is in a field of its own with a base of 16.  This means it has 16 different values that represent a digit.  Let’s relate it to both binary and denary here in this table. 

 

One can only admire a numerical system that uses letters as well as numbers.

As crazy as it looks, hex is in fact an excellent means of shortening complex binary digits into something much more readable for our simple species.  HTML colour codes, mac addresses and Assembler all uses hex, and if you think about it is is much easier to remember:

542DC0

…than the equivalent binary of:

0101 0100 0010 1101 1100 0000

30 Second Read #2 – What is Binary?

Binary digits (also known as bits) are the very essence of computers. Computers are powered by electrical switches, which operate in a state of either being On or Off.*

The On state of a switch is represented in binary by the number 1, and the Off state is a 0 in binary.  

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That’s all there is to computers – 1s and 0s.  Everything a computer does, receives, inputs, processes, stores, outputs and cogitates upon is in binary.  Every programming language – even Assembler – has to be converted to binary for a computer to run it. Every key press, microphone signal, VR headset, Kinect motion, every every everything is in binary.  You get the point. Most people view bits in groups of 8 – and this is known as a byte.  4 bits are also quite common, especially in hexadecimal calculations.  Being half a byte, 4 bits are known as a nibble.  I love the fact that this is no joke and is in fact a genuine computing term.  Binary can be easily converted to denary or decimal, so that we simple humans can get to grips with it:

128	64	32	16	8	4	2	1	Denary
1	0	1	1	0	1	1	1	183
0	1	0	0	1	1	0	0	76
1	1	1	1	1	1	1	1	255

Some people have learned a huge number of binary digits to the extent that they do not need to manually convert them as above – they simply remember them.  This makes them very impressive computer scientists. But not necessarily invited to the best parties.

30 Second Read #1 – What is Computing?

Computing is defined by the Cambridge English Dictionary as the activity, study, or job of using computers.  The terms Computing and Computer Science are often used interchangeably in schools, colleges and universities.  It boils down to studying the hardware, the software, and the information processes that underpin computers.

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A computer nowadays can of course be a standard PC or Mac, a laptop, an Xbox, a smartphone, a smartwatch, a smart tv… er…. a smart car…um…. a smart heating system.  Plenty of smart things, and quite a few things that really are not at all smart, but use some form of microprocessor, such as a traffic light.

Information and data play a huge part in our lives, and consequently if you study computing you are likely to encounter information-related concepts such as binary, denary and hexadecimal numbering systems, logic circuits and concepts, data transmission, computer architecture, data storage and memory, databases and algorithms.  Plus of course programming, as in coding – the one that everybody thinks of nowadays. Programming is a better term.

You will also learn about security practices, data breaches (very topical at the moment), encryption, maybe quantum computation, hopefully Artificial Intelligence, and the ethics of using computers.

In all, it is a huge, and hugely exciting, field to study.  But then I would say that.