BTec Level 3Extended Diploma in Creative Media Production HA1 - Technical File – Ashleigh Darlington.
BTec Level 3Extended Diploma in Creative Media Production HA1 - Technical File – Raster images. A raster image, also called a bitmap is a way to represent digital images. The raster image takes a wide variety of formats. A raster image represents an image in a series of bits of information which translate into pixels on the screen. These pixels form points of colour which create an overall finished image. When a raster image is created the image on the screen is converted into pixels and each pixel is assigned a specific value which determines its colour. When a raster image is viewed, the pixels usually smooth out visually for the user who sees a photograph or drawing, when blown up the pixels in a raster image become apparent. Depending on resolution, some raster images can be enlarged to very large sizes, while others quickly become difficult to see. The smaller the resolution, the smaller the digital image file, for this reason people who work with computer graphics must find a balance between resolution and image size. Resolution refers to the number of pixels per inch (PPI) or dots per inch (DPI) in the image. The higher the resolution the greater the number of pixels, this allows a greater radiation of colour that will translate better as the image is enlarged. The more pixels, the more individual points of data to be stored, as well. For high quality photography, a high DPI is preferred because the images will look more appealing to the viewer. For small images which do not need to be blown up, or when quality is not important, a http://www.wisegeek.com/what-is-a-raster- low DPI can be used image.htm
HA1 - Technical File – Vector imagesVector graphics is the use of geometrical primitives such as lines, curves, points and shapes or polygons which are all based on mathematical equations to represent images in computer graphics.These are instances where working with vector tools and formats is the best practice. There are times when both formats come together. An understanding of the advantages and limitations of each technology and the relationship between them is most likely to result in efficient and effective use of tools.Vector graphics formats are complementary to raster graphics, which is the representation of images as an array of pixels as its typically used for the representations of photographic images Vector graphics are stored as mathematical expressions as opposed to bit mapped graphics which are stored as a series of mapped dots, also known as pixels (picture cells) There are instances when working with vector tools and formats is the best practice, and instances when working with raster tools and formats is the best practice. This example shows the effect of vectorVector formats are not always appropriate in graphics work because devices such graphics versus raster graphics> The as cameras and scanners produce raster graphics that are impractical to original vector based illustration is the one shown at the left. The lower right convert into vectors. image illustrates the same magnification as a bitmap image. Vector images can be scaled indefinitely without degrading quality.
Anti-aliasing. In digital signal processing, spatial anti-aliasing is the technique of minimizing the distortion artefacts known as aliasing when representing a high resolution image at a lower resolution. Anti-aliasing is used on digital photography, computer graphics, digital audio, and many other applications. Anti-aliasing means removing signal components that have higher frequency than is able to be properly resolved by the recording (or sampling) device. The removal is done before sampling at a lower resolution. When sampling is preformed without removing this part of the signal, it causes undesirable artefacts such as the black and white noise near the top of figure 1-a below. In this approach, the ideal image is regarded as a signal. The image displayed on the screen is taken as samples, at each (x,y) pixel position, of a filteredAbove left: an version of the signal. Ideally, we would understandaliased version of how the human brain would process the originala simple shape.Above right: an signal, and provide an image on screen that will yieldanti-aliased the most similar response by the brainversion of thesame shape.Right: The anti-aliased graphic at5x magnification.
Image Resolution Image resolution describes the detail an image holds. The term applies to raster digital images, film, images, and other different types of images. Higher resolution means more image detail. Image resolution can be measured in various ways. Basically resolution quantifies how close lines can be to each other and still be visibly removed. Resolution units can be tried to physical sizes to the overall size of the picture or to angular subtenant. Line pairs are often used instead of lines, a line pair compromises a dark line and an adjacent line. A resolution of ten lines per millimetre. Photographic lens and film resolution are most often quoted in line pairs per millimetre. Spatial Resolution:The measure of how closely lines canbe resolved in an image is called spatialresolution, and it depends on properties A classic test targetof the system creating the image, not used to determinatejust the pixel resolution in pixels per spatial resolution of imaging sensors andinch. imaging sensors.
Aspect Ratio.The aspect ratio of an image is the ratio of the width of the image to itsheight, expressed as two numbers separated by a colon. That is for an x:yaspect ratio, no matter how big or small the image is, the width is dividedinto x units of equal length and the height is measured using the samelength unit, the height will be measured to be y units.Aspect ratios are mathematically expressed as x:y and Xxy with the letterparticularly used for pixel dimensions. Cinematographic aspect ratios areusually denoted as a decimal multiple of width vs. unit height.The most common aspect ratios used today in the presentation of films inmovie theatres are 1.85:1 and 2.39:15 commonaspect ratios:
File FormatsA file format is the standard way that information is encoded forstorage in files on the computer . It specifies how certain bits areused to encode information.GIF: This stands for Graphics Interchange Format, it is a bitmap image format that was introduced byCompuServe in 1987 and due to its wide support and portability it developed into widespread usage on theWorld Wide Web. The format supports up to 8 bits per pixel, this allows a single image to reference a pallet upto 256 distinct colours. It also supports animations. The colour limitation makes the GIF format unsuitable forreproducing colour photographs and other images that have continuous colours, but it works better withsimpler images such as graphics or logos.TIFF: This stands for Tagged Image File Format and this is used for storing images and it used mostly by graphic artists,people in the publishing industry and both amateur and professional photographers in general. Tiff formats are widely supportedby image manipulation applications, by publishing and using page layout applications.EPS: This stands for Encapsulated PostScript this is a conforming PostScript document that has additional restrictions which areintended to be useful as a graphics file format. EPS files are more or less self contained. It is a standard graphics file format forexchanging images, drawings (such as a logo or map) or even layouts of complete pages.PSD This is a Proprietary File Format that is used to create and edit images in Adobe Photoshop, which is a Graphics EditingProgramme. It is a widely accepted format as it supports all available image types – Bitmap, RGB, Duotone, Grey scale, IndexedColour, CMYK, Lab, and Multichannel. PDF: This stands for Portable Document Format and it was developed in the early 1900’s. It is used to represent documents independently of application software, hardware and operating systems. Every PDF file encapsulates a complete description of a fixed-layout flat document this includes: font, text, graphics and other information. JFIF: This stands for JPEG File Interchange Format and this is a standard image file format. It is a format for exchanging JPEG encoded files compliant with the JPEG interchange format (JIF) standard. It solves some of JIFs limitations in regard to simple JPEG encoded file interchange and as with all these files, image date with them is compressed by using the techniques in the JPEG standard.
Color models.A color model is am abstract mathematical model by describing the way colours can represented as tuplesof numbers, typically as three or four values or colour components. When the model is associated with aprecise description of how the components are to be interpreted.CMYK Colour Model RGB Color Model Recognizing that the geometry of the RGB model is poorly aligned with theColor color-making attributes recognized by human vision, computer graphicsprinting researchers developed two alternatetypically representations of RGB, HSV anduses ink of HSL. HSV and HSL improve on the color cube representation of RGB byfour colors: arranging colors of each hue in a radialcyan, slice, around a central axis of neutralmagenta, colors which ranges from black at theyellow, and bottom to white at the top. The fully saturated colors of each hue then lie inkey (black a circle, a colour wheel. The CMYK color model (process color, four color) is a subtractive colour model used in colour printing, and is also used to describe the printing process itself. CMYK refers to the four inks used in some color printing: cyan, magenta, yellow, and key (black).
Adobe PhotoshopAdobe photoshop is a graphics editing program developed and published by AdobeSystems incorporated.Adobe Photoshop is released in two editions: Adobe Photoshop, and AdobePhotoshop Extended, with the Extended having extra 3D image creation, motiongraphics editing, and advanced image analysis features. Features Photoshop uses color models RGB, lab, CMYK, greyscale, binary bitmap, and duotone. Photoshop has the ability to read and write raster and vector image formats such as .EPS, .PING, .GIF, and .JPEG. Photoshop has ties with other Adobe software for media editing, animation, and authoring. Photoshop has ties with other Adobe software for media editing, animation, and authoring.
Adobe IllustratorAdobe Illustrator is a vector graphics editor developed and marketed AdobeSystems. Illustrator is similar in scope, intended market, and functionality to itscompetitors, Corel Draw and Macromedia Free Hand. Features Among the new features included in Illustrator CS2 were Live Trace, Live Paint, a control palette and custom workspaces. Live Trace allows for the conversion of bitmap imagery into vector art and improved upon the previous tracing abilities. Live Paint allows users more flexibility in applying color to objects, specifically those that overlap. In the same year as the CS2 release, Adobe Systems announced an agreement to acquire Macromedia in a stock swap valued at about $3.4 billion and it integrated the companies operations, networks, and customer- care organizations shortly thereafter. Adobe now owned FreeHand along with the entire Macromedia product line and in 2007, Adobe announced that it would discontinue development and updates to the FreeHand program. Instead, Adobe would provide tools and support to ease the transition to Illustrator.
Adobe IndesignAdobe InDesign is a software application produced by Adobe Systems. It can beused to create works such as posters, flyers, brochures, magazines, newspapersand books. In conjunction with Adobe Digital Publishing Suite InDesign can publishcontent suitable for tablet devices. Graphic designers and production artists are theprincipal users, creating and laying out periodical publications, posters, and printmedia. It also supports export to EPUB and SWF formats to create digitalpublications, and content suitable for consumption on tablet computer devices. TheAdobe in copy word processor uses the same formatting engine as InDesign.