Glossary

1. Pixel- In digital imaging a pixel is a physical point in a raster image or the
smallest addressable element in a display device so it is the smallest
controllable element of a picture represented on the screen. The address of a
pixel corresponds to its physical coordinates.The term pixel is actually short for
Picture Element.These small little dots are what make up the images on digital.
The screen is divided up into a matrix of thousands or even millions of
pixels.Each pixel can only be one colour at a time. However, since they are so
small, pixels often blend together to form various shades and blends of
colours. The number of colours each pixel can be is determined by the number
of bits used to represent it.
Resolution - Refers to the sharpness and clarity of an image. The
term is most often used to describe monitors, printers, and bit-mapped graphic
images.Bitmap images are composed of pixels. Image resolution is simply the
number of Pixels Per Inch (PPI)in the bitmap grid.There are two aspects to
every bitmap image - its size(width and height in inches) and resolution(the
number of pixels per inch). These two factors alone determine the total
number of pixels in an image. Some of the typical resolutions include;
256x256- Found on very cheap cameras, this resolution is so low that the
picture quality is almost always unacceptable. This is 65,000 total pixels.
640x480 - This is the low end on most "real" cameras. This resolution is ideal
for e-mailing pictures or posting pictures on a Web site. 4064x2704 - A top-of-
the-line digital camera with 11.1 megapixels takes pictures at this resolution.
At this setting, you can create 13.5x9 inch prints with no loss of picture quality.
The more pixels there are in an image, the more detail the image can be
displayed with. The fewer pixels there are in an image, the less detail the
image can be displayed with. There are two ways to display an image - on
screen and in print. The standard for screen displays is 72 PPI.The standard for
Print is 300 PPI.

2. Screen Ratios - The aspect ratio of a screen or image describes
the proportional relationship between its width and its height.It is commonly
expressed as two numbers separated by a colon, as in 4:3 and 16:9. The most
common aspect ratios used today in the presentation of films in movie
theatres are 1.85:1 and 2.39:1. Two common video aspect ratios are
4:3(1.33:1), the universal video format of the 20th century. And 16:9 (1.77:1),
universal for high-definition television and European digital television.In still
camera photography, the most common aspect ratios are 4:3, 3:2, and more
recently being found in consumer cameras 16:9. This is important as many
DSLRs are being used to shoot video due to the quality of their internal sensors
and superior lenses. With television, DVD and Blu-ray Disc, converting formats
of unequal ratios is achieved by enlarging the original image to fill the receiving
format's display area and cutting off any excess picture information (zooming
and cropping). By adding horizontal mattes (letterboxing) or vertical mattes
(pillarboxing)to retain the original format's aspect ratio.
Pixel Aspect Ratio describes the relationship between the width and height of
a single pixel.Different pixel aspect ratios are the reason why two video images
with identical frame sizes can appear as different sizes on screen.If width =
height, then the pixel is square and the aspect ratio (width÷height) = 1.0.
Frame Rate - The human eye and its brain interface, the human
visual system, can process 10 to 12 separate images per second, perceiving
them individually. Early silent films had a frame rate from 14 to 24 FPS which
was enough for the sense of motion, but it was perceived as jerky
motion.Persistence of vision was a commonly-accepted although somewhat
controversial theory which states that the human eye always retains images
for a fraction of a second on the retina (around 0.04 second).

3. Frame Rate tells you how many frames per second there are when recording or
playing video/dvd. Video cameras in Europe use 25 frames per second (fps). In
USA & Japan 29.97fps or 30fps is used.Animation works by recording each
frame individually (e.g. with a stills camera) and then playing them back at a
frame rate. They also often work with a lower frame rate (e.g. 12fps) so less
frames are needed for the same length video clip.Frame rate is most often
expressed in frames per second (FPS) and is also expressed in progressive scan
monitors as hertz (Hz).
Video Formats–A video format defines the way in which video is
recorded and stored. It normally specifies: Codec/Compressor, Frame Rate,
Frame Size, Frame Aspect Ratio, Pixel Aspect Ratio, Scanning Method. Some
common formats are DV, HDV, AVCHD. Tape based formats such as DV and
HDV can be transferred to a computer for editing via firewire. File based
formats such as AVCHD are already stored as files and can be transferred to a
computer for editing via USB or card reader. File-based formats may need to
be converted during or after transfer to compatible with editing software.
Compression–Codec is short for coder-decoder and describes the
method in which video data is encoded into a file and decoded when the file is
played back. Most video is compressed during encoding, and so the terms
codec and compressor are often used interchangeably.