1. Pixel
Pixels are essentially samples of an original image. They are the smallest element in a display device such as
an LCD screen in which the image displayed on the screen is made up of a very large number of pixels put
together. Pixels can be a measurement of resolution
for example resolution of an image can be classed
as 2400 pixels per inch or spaced x number of pixels
apart. It is most commonly described as two
numbers for example a resolution of 640 by 480
meaning simply that there are 640 pixels from left
to right and 480 from top to bottom. This would
therefore indicate that the total number of pixels in
the image is 640 x 480 = a total of 307,200 pixels
Resolution
Resolution is simply the level of detail an image holds. The higher the resolution the more detail in the image.
Resolution can apply to types of digital images, film images and many other types of media. With many
different media outlets resolution has a wide variety of
meanings including things like pixel resolution and spectral
resolution. The main definition of resolution when media
images are concerned is the quality of the image and how
many pixels are included. The image shown here
demonstrates different resolutions of an image shown in the
order of lowest to highest DPI (dots per inch).
Screen ratios
The basic concept of screen ratios or aspect ratio is the correlation between an images height and its width.
The expression of aspect ratio is most commonly two numbers separated by a colon, e.g. 16:9 this is called an
X:Y aspect ratio, for this to work the numbers do
not specifically have to be the written number they
just have to divide into x units of equal length and
the same with y. For example a group of images
that would all fit into the category of 16:9 could
consist of an image of 16 inches by 9 inches, an
image of 16cm by 9cm and even an image of 8 yards
wide and 4.5 yards high. The image shown here
demonstrates some commonly used aspect ratios
This demonstrates how aspect ratio is not used to
show the actual size of an object it is simply the
dimensions.
Frame rate
To get a good understanding of frame rate, first a brief understanding of the actual meaning of the word
frames must be established. Frames in this context is used to describe the brief sections in any motion image,
such as computer graphics, film and pretty much any motion capture methods. The video only comes together
to appear as though it is moving because of a large amount of pictures being projected at high speed. A frame
is one of these pictures alone; so frame rate (or frames per second) is simply the rate at which the frames are
projected onto the screen. With this being the case, a high frame rate describes a video in which the frames
are being projected one after another at a high speed, this makes the video appear smoother and flow well, a
frame rate for this would be something like
25fps which is the frame rate used for most
standard definition television broadcasts.

2. Video formats
Compression
Compression is a very useful tool for many different computer users with many different tasks to complete.
Data compression, formally known as source coding is essentially the method of taking a file and using other
software to make the file much smaller but still contain the important elements for the file to run again.
Unfortunately files can’t be compressed and then used and
stored as smaller files; the file would need to be
decompressed in order to be run again. Data compression
does still have some obvious uses however such as
transferring data and storing more data due to the
reduced space those files need. Compressing data can be
either ‘lossy’ or ‘lossless’. Lossless compression reduces
the file size by finding and deleting redundancy in the file,
which is essentially wasted space in the file. In this
method of data compression no information is lost so
therefore this is the preferred method. Lossy compression
reduces the size by locating unnecessary information and
deleting it.