Multimedia

Standard and Higher Level

Graphics, video, audio and interactive applications are all used across multiple types of projects and products such as games, movies, television programmes, scientific work, computer visualisations, computer generated imagery (CGI).

Hardware has struggled to keep up with the needs of the masses, and the Internet has developed since Web 2.0 to deliver high quality interactive content on the fly even to the smallest of devices such as smartphones.

Bitmap Graphics

Images that are comprised of a rectangle of tiny dots known as pixels. If the image has a higher number of pixels, then the resolution is higher, which in turn means that the quality is higher as the image can hold more detail. MS Paint for Windows is a good example of an application that can create and edit Bimaps.

Editing Tools

Image editing tools allow for advanced manipulation of graphics to suit a user's needs. The type of editing that can be done includes:

  • Cropping - Taking a focused part of an image, and removing everything else. This can often alter the impact of an image. For example, removing various people out of the side of an image to make it appear as if they weren't involve with the event.
  • Scallng - Increasing or reducing the size of an image. Maintaining the aspect ratio of an image is important when scaling (the ratio between the width and height so it does not appear distorted. Flipping and Rotation tools are also available in most image editing software.
  • Cloning - Taking part of an image and replicating it in the same image to cover over something. For example, covering a skin blemish by copying some skin without blemishes and pasting it over the top of the blemish.
  • Layering - As the name suggests these are commonly used for stacking images over the top of one another. Like the previous example to cover a skin blemish in a photograph, the replacement would be placed on it's own layer over the top of the existing image.
  • Filters - These have become synonymous with apps such as Instagram. They essentially change the contrast, colour, saturation, shadow, warmth etc of an image. They can also be used to sharpen or blur an image or add artistic effects such as photo frames.

Social Impacts

Users can now appear exactly how they want to appear to the masses. By using photo editing, they can remove those skin blemishes or even alter skin tone, they can alter how much they appear to weigh, they can change eye colour and so on...
While it is deemed that this is mostly done for fun and entertainment, it is not always clear that a photo has actually been edited. So what kind of impression is this giving to people, and what are the younger generation aspiring to?

Health and Social

Altering images of celebrities in magazines and websites for the public eye has contributed to a stereotypical image of what is deemed attractive. The images often portray unrealistic goals for those who look up to them, which can in term lead to negative mental health amongst teenagers, and even eating disorders.

Legal Impacts

There have been several cases of where image manipulation has been used as evidence in high profile cases. Donald Trump has famously coined the term 'fake news' in the past year and image manipulation has played a part in that. One site in Singapore known as 'The Real Singapore' was taken down after it was allegedly including defamatory comments and potentially faked images.

Political Impacts


Altering of digital content for political gains is not a new thing. It has been going on for many years, from since Abraham Lincoln's head was imposed onto the image of another (above) to make him look more majestic, to G.W. Bush reading a children’s book upside down, but then having it clearly altered from the original image, to show to the right way up.

Scientific Impacts

One of the most scientific breakthroughs in modern history was the Moon landings in 1959 by the USA. To this day, it is disputed that the footage and imagery of this event may be faked. These are conspiracy theories, but with the ability to doctor and manipulate images and videos so easily with a high authentic feel, people just can't rule it out.

Digital Fakes

A recent development is for professionals to replicate famous figures in videos in real time using one piece of AI software. The video below shows it in action.

It's almost impossible to detect that this a fake, and therefore many people could be influenced as a result. Only common sense of realising what is not realisitic and checking directly with the source can detect the fake. Technology could also be used to detect the fake, but not everyone has access to that technology!

Image Storage

Bitmaps are represented by a rectangle of pixels on the screen. The resolution of that image is shown as a number x a number (E.g. 1024x768). The more pixels, means the higher the resolution, means the higher quality of image.

Digital cameras often quote their resolution in megapixels, for example, the Samsung S8+ has a 12Mp camera (12 million pixels), which shows the number of pixels captured in one picture, not the width or height. Computer screens are now measured in pixels per inch (PPI).

Bit Depth

Also known as colour depth, this is the number of bits used to store each pixel in the image. If the bit depth is higher, then the image can have more colours. This comes at a trade off though as it means the image will take up more space.
A 1-bit image can have 2 colours (as a bit can be a 0 or a 1), a 2-bit four colours (00, 01, 10, 11), all the way up to 32 bit (4 bytes per pixel) which could have 4,294,967,296 possible colours.

Storage Requirements

Storage requirements for an image can be calculated with the following formula:
width x height x bit depth
So if we had our image that was 1024x768 and was in 32-bit colour, the calculation would be as follows:
1024 x 768 x 4 (32-bits . = 4 bytes) = 3,145,728 bytes
3,145,728 / 1024 = 3072KB
3072 / 1024 = 3MB
This calculation only gives the maximum storage requirement, but through compression of various file formats the size is often smaller.

Compression - Lossless vs Lossy

Compression aims to reduce the size of a file by removing and reducing the amount of redundant data in an image. 2 mains methods are called 'lossless' and 'lossy' compression.

Lossless compression

Lossless compression looks at the colour of each pizel in an image and assigns it a decimal value (see the table shown below). The second to bottom row of that image would be represented as 4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,5,5,4,5,5,5,5,4,4,4,4 (4 = yellow, 5 = dark yellow) which would mean repeated values.
To reduce the data needed to store the image colour information, this could be shortened to 15,4,2,5,1,4,4,5,3,4 (15 yellow pixels, 2 dark yellow... and so on).
Lossless compression is used in cases where it is important that the original and the decompressed data be identical, or where deviations from the original data would be unfavourable. Examples include PNG or GIF formats. It uses the patterns of data and represents them in a way that takes up less space, hence making the image file size smaller. While the compression gains in storage space are good, lossless compression only works well with images that have solid blocks of colour, so using it for photographs often struggles to make much difference.

Lossy compression

Lossy compression uses inexact approximations and partial data discarding to represent the content. The amount of data reduction possible using lossy compression is much higher than through lossless techniques. It does this by getting rid of data that it thinks a user might not miss; Either two very similar colours in an image will be combined into one, or what is deemed background noise in an audio file might be removed. Even when noticeable by the user, further data reduction may be desirable (e.g., for real-time communication, to reduce transmission times, or to reduce storage needs).

Compression formats

Any type of data has the potential to be compressed, from images to audio to documents. Common formats for general file compression include ZIP using Winzip, and RAR using Winrar.

PPI & DPI

Pixels per inch means the amont of pixels are displayed in every inch of an output; on screen or on a printout. This then defines what the physical size of the output would be and how sharp it will appear. For example, an image 1024 x 768 printed at 150PPI would be 6.8 inches by 5.1 inches. (1024/150 x 768/150)

Dots per inch refers to the resolution of a printer. ie. The number of dots that a printer produces with ink when printing an image.
It's different to PPI because a printer may use more than one dot of ink to print a pixel.

Vector Graphics

Vector graphics are not based around pixel data but rather objects that are defined as mathematical equations. Meaning if a vector graphic is scaled up, it does not become distorted or pixelated. Due to vectors being more complex than pixel based graphics, they do require more processing power to handle the calculations.

File Formats

Some common multimedia file formats include:
Video
  • AVI
  • MP4
  • MOV
  • Audio
  • MP3
  • AAC
  • WAV
  • Image
  • BMP
  • JPG
  • PNG
  • GIF
  • Digital Audio

    A very popular method of distributing music these days is through services such as Spotify or Apple Music. The songs are recorded and converted into a digital format so that they can easily be distributed over the web. Audio editing can be done by manipulating the sound in the form of waves shown on screen. The sampling rate of an audio file is based on how many times per second that a sample of the analogue data is taken to convert to digital. The higher the sampling rate, the better quality the audio. This is not to be confused with bit-rate which is commonly used to describe the quality of digital audio files. MP3 files have bit rates from between 32 Kbit/s to 320Kbit/s. Lower bit rates are lower quality but smaller files.

    Digital Video

    Digital video content is available via services such as YouTube or Netflix, where the usual method of distribution is via streaming. Files stored locally on a machine will have to be read using software known as CODECS (compressor decompressor), which tells the computer how decode the file for that method of compression.
    Streaming services show video content by downloading or 'buffering' a portion of the file enough to view several minutes, then while the user watches those minutes, the next few minutes are queued up in the buffer. This means that a user does not need to download an entire video file before watching it.

    Intellectual Property

    Intellectual property (or "IP") is a category of property that includes intangible creations of the human intellect, and primarily encompasses copyrights, patents, and trademarks. It also includes other types of rights, such as trade secrets, publicity rights, moral rights, and rights against unfair competition. Artistic works like music and literature, as well as some discoveries, inventions, words, phrases, symbols, and designs can all be protected as intellectual property. Intellectual property law has evolved over centuries. It was not until the 19th century that the term "intellectual property" began to be used, and not until the late 20th century that it became commonplace in the majority of the world.

    The intangible nature of intellectual property presents difficulties when compared with traditional property like land or goods. Unlike traditional property, intellectual property is indivisible – an unlimited number of people can "consume" an intellectual good without it being depleted.

    Some countries allow exception to copyright laws in particular circumstances such as when reporting news, if there is any joke around the content, or if a student was using content for a school project.

    DTP and Word Processing

    Word processing software offers the ability to type up line by line documents usually focused mainly on text. They allow the changing of format, fonts, colours and the interspersement of images and other content such as tables. Desktop publishing software allows more manipulation of layout and focuses more on creating things such as posters, articles and books. Both types of software provide a WYSIWYG interface (what you see is what you get) to allow the user to preview what the document would look like in a printed format. Both softwares also allow for the saving of documents using different file formats.

    PDF vs Plain Text vs Docx

    PDF - Portable Document Format is commonly used for distributing documents either via the web, email or on media. The format supports embedded fonts, so the document will always have the correct font, even if the machine viewing the content doesn't have that font installed. PDFs can be created by popular word processors these days like Microsoft Word, but editing a PDF can only be done using bespoke software such as Adobe Writer.

    Plan text - this format stores only text content. There is no formatting or images or tables or anything else. They are used commonly in operating systems for storing system logs. If one needs a basic document with some formatting included, then it can be saved as an RTF (Rich Text Format) which allows some formatting and inclusion of images.

    Word document (.docx) - Microsoft have their own file format because it contains features and information that only Microsoft Word can interpret. DocX format can be read by other open source versions of Office software, or web based Office apps, but ultimately works best with Microsoft Word.

    Presentations

    This software is an excellent way to communicate plans, ideas, facts, and opinions to many people at one time. The idea of this software is to be shown or projected to larger groups of people. There are many festures within presentation software such as being able to print notes or smaller versions of the slides fit to one page to accompany a talk. There is a risk of becoming boring with presentations by reading the content to everyone off each slide, but the best presenters aim to just use the presentations as a visual aid to accompany or support what they are talking about.

    Other Resources

    Paper 1

    Slightly different examinations for SL and HL, based on answering 20 mark questions on a selection of the course topics.

    Paper 3

    For HL students only, answering questions on the pre-seen case study. This year is 'A Doll Called Alicia'.

    Extended Essay

    Details and recommendations for students considering writing their Extended Essay in ITGS.

    Command Terms

    How to approach examination questions that use each of the prescribed command terms for ITGS.