BTec Level 3Extended Diploma in Creative Media Production

BTec Level 3Extended Diploma in Creative Media Production

HA1 - Technical File – Raster and Vector Images

 There are two kinds of computer graphics: Raster Graphics, these graphics are made of pixels, and Vector Graphics that are made of paths. Raster images are often referred to as bitmap images.

A bitmap or raster image uses lots of individual pixels where each pixel can be a different colour or shade - Bitmaps are composed of pixels.

Vector graphics use mathematical relationships between points and the paths connecting them to describe an image - Vector graphics are composed of paths

http://en.wikipedia.org/wiki/Raster_graphics

• Antialiasing is a technique sometimes referred to as Oversampling. It is used in computer graphics for smoothing out jagged lines that occur due to the output device not having enough resolution to create a smooth line.

• Antialiasing works by surrounding the jagged lines with intermediate shades of colour similar to the colour of the line This works to blend the colour into looking more like a straight line than a jagged shape.

• The only downfall with Antialiasing Is that although it reduces the jagged effect of the lines it also makes them appear fuzzier.

HA1 - Technical File – Antialiasing

• In computer graphics the resolution of something is the number of pixels in each dimension that can be shown.

• Resolution is usually measured as Width x Height with the units in pixels, for example 1024 × 768 meaning the width is 1024 pixels and the height is 768 pixels.

• The with and hight differences create different aspects like widescreen for example.

• As far as the Image quality is concerned higher numbers of pixels are better this creates a better quality image on the screen.

HA1 - Technical File – Resolution

• The aspect ratio of an image describes the difference between the width and the height.

• This can often be written as two numbers separated by a colon for example 16:9 this can relate to images of any size for example 16 cm wide and 9 cm high or even 16 yards wide and 9 yards high.

• 4:3 is the standard for computers and old televisions whereas 16:9 is widescreen and the usual HD format.

HA1 - Technical File – Aspect Ratio

• A GIF or Graphics Interchange Format is a bitmap image format that also supports animations. A GIF only has 256 distinct colours for each frame making it unsuitable to replicate real colour photographs but for images like Logos a GIF is perfect.

• A JPEG is a very commonly used method of compression for digital photography. The amount of compression can be altered in order to differ between storage size and image quality

• A TIFF or a Tagged image file format is a file format for storing images that is popular for graphic artists, publishers and photographers.

• An EPS or an Encapsulated PostScript is a DSC confirming Post script document which is intended to be usable as a graphics file format and has restricted content.

• A PSD stands for a Photoshop document. Basically a PSD file stores an image with support for most of the imaging options available in Photoshop

• PDF stands for Portable Document Format. A PDF file is used to show documents without operating software. Each PDF file creates a complete description of the document including text, fonts, graphics and anything needed to display it.

HA1 - Technical File – File Formats

• RGB is a colour model used in digital graphics that basically involves red green and blue light being added together in various combinations to create a wide variety of colours. The name RGB comes from the three primary colours red, green and blue. Typical things that use RGB include Televisions such as LCD and Plasma, computer and mobile phone displays.

• CMYK is another colour model used in digital graphics. CMYK comes from the four colours used, Cyan, Magenta, Yellow and Key(Black). The CMYK model works by partially or completely masking colours on a lighter, usually white, background. The ink reduces the light that would otherwise be reflected.

HA1 - Technical File – Colour Models