BTec Level 3Extended Diploma in Creative Media Production
BTec Level 3Extended Diploma in Creative Media ProductionHA1 - Technical File – Luke Finlay
BTec Level 3Extended Diploma in Creative Media ProductionHA1 - Technical File – Raster and Vector ImagesA raster image is a collection of dots called pixels. Each pixel is a tiny coloured square. Whenan image is scanned, the image is converted to a collection of pixels called a raster image.Scanned graphics and web graphics (JPEG and GIF files) are the most common forms ofraster images.The resolution of a raster image is expressed in terms of the dots per inch. A printer orscanners resolution is also measured in dots per inch. Typical desktop laser printers print at 300- 600 dpi. Image setters are capable of printing over 2,500 dpi. Printers with higher dpi ratingsare capable of producing smoother and cleaner output. The output quality of a printing device isdependent upon the resolution of a bitmap or scan. A 300 dpi raster image will output at thesame quality on a 300 dpi laser printer as on a 2,500 dpi image setter.With any scanned colour image, a large number of colours will be required to render a rasterimage reproduction of the original source artwork accurately. If scanned at 24-bin colour depth(16 million colours), most human eyes could not tell the difference between the original imageand the scanned raster image. Now if you scan the same image using the palette of 256colours, it would be impossible to accurately reproduce the original colours because you have asmaller colour palette to choose from. To get around this, scanners use a process calleddithering to approximate colours that dont occur in the current colour palette.Common raster image formats include BMP (Windows Bitmap), PCX (Paintbrush), TIFF (TagInterleave Format), JPEG (Joint Photographic Expert Group), GIF (Graphics InterchangeFormat) , PNG (Portable Network Graphic), PSD (Adobe Photoshop) and CPT (Corel PhotoPAINT).Raster Images
BTec Level 3Extended Diploma in Creative Media ProductionHA1 - Technical File – Raster and Vector ImagesVector ImagesA vector image is a collection of connected lines and curves that produce objects. When creating a vectorimage in a vector illustration program, drawing points are inserted and lines and curves connect notestogether. This is the same principle as "connect the dots". Each line and curve is defined in the drawing by thegraphics software by a mathematical description. Every aspect of a vector object is defined by math includedline length and on down the line. Text objects are created by connecting lines and curves. Every letter in a fontstarts out as a vector object. Vector images are object-oriented while raster images are pixel oriented. Avector object will have a "wireframe" underneath the colours in the object. In a vector object, colours are likeclothes over the top of a skeleton. CorelDraw and Illustrator create text and objects using vectors that can beeasily manipulated.Vector images are defined by math, not pixels. They can be scaled up or down without any loss of quality.When an illustration program sizes a vector image up or down, it simply multiplies the mathematicaldescription of the object by a scaling factor. For example a 1" square object would need to be multiplied by afactor of 2 in order to double in size. The math is simply recalculated to produce an object twice the size of theoriginal. Because vector images scale up or down without the loss of image quality, they can be output at anyresolution that a printer is capable of producing. Unlike raster images, quality is not limited by dots per inch orscanning resolution.Since vector images are composed of objects not pixels, you can change the colour of individual objectswithout worrying about individual pixels. Colouring vector objects is similar to colouring with crayons in acolouring book. A drawing program will enable a user to click inside an object and define its colour. A drawingprogram will also enable a user to define the colour and width of lines.Common vector formats include EPS (Encapsulated PostScript), WMF (Windows Metafile), AI (AdobeIllustrator), CDR (CorelDraw), DXF (AutoCAD), SVG (Scalable Vector Graphics) and PLT (Hewlett PackardGraphics Language Plot File)Source: http://www.signindustry.com/computers/articles/2004-11-30-DASvector_v_raster.php3
BTec Level 3Extended Diploma in Creative Media ProductionHA1 - Technical File – Raster and Vector ImagesRaster Image Vector Image
BTec Level 3Extended Diploma in Creative Media ProductionHA1 - Technical File – AntialiasingAntialiasing is a filter used before a signal sampler, to restrict the bandwidth of a signal to approximately satisfythe sampling theorem. Since the theorem states that definite explanations of the signal from its samples ispossible when the power of frequencies above the Nyquist frequency is zero, a real anti-aliasing filter cangenerally not completely satisfy the theorem. A realizable anti-aliasing filter will typically permit some aliasing tooccur; the amount of aliasing that does occur depends on how good the filter is and what the frequency contentof the input signal is.Antialiasing is commonly used at the input of digital signal processing systems, for example in sound digitizationsystems; similar filters are used as reconstruction filters at the output of such systems, for example in musicplayers. In the later case, the filter is to prevent aliasing in the conversion of samples back to a continuoussignal, where again perfect stop-band rejection would be required to guarantee zero aliasing.The theoretical impossibility of realizing perfect filters is not much of an impediment in practice, though practicalconsiderations do lead to system design choices such as oversampling to make it easier to realize "goodenough" anti-aliasing filters.
BTec Level 3Extended Diploma in Creative Media ProductionHA1 - Technical File – ResolutionBitmap images are composed of pixels. Image ‘resolution’ is simply the number of Pixels Per Inch (PPI) inthe bitmap grid. There are two aspects to every bitmap image - its size (width and height in inches) andresolution (the number of PPI). These two factors alone determine the total number of pixels in an image.For example, a 2 inch by 3 inch image with a resolution of 300 pixels per inch contains (2 x 300) x (3 x 300)or 540,000 pixels.The more pixels there are in an image, the more detail the image can be displayed with. The fewer pixelsthere are in an image, the less detail the image can be displayed with. There are two ways to display animage - on screen and in print. When you are preparing images you need to know what resolution to scan orsize them to. There is an optimum resolution for each and it is very easy to determine.First let us take up screen display. This is the easiest to determine. Scan or size them all to 72 PPI. Why? Amonitor on a Macintosh system displays at 72 PPI. A monitor on a Windows system displays at 96 PPI.Though there is a difference between the two, the standard for screen displays is 72 PPI.Better resolutionBad Resolution
BTec Level 3Extended Diploma in Creative Media ProductionHA1 - Technical File – Aspect RatioThe aspect ratio is an image projection attribute that describes the proportional relationship between thewidth of an image and its height .It is expressed as two numbers separated by a colon. That is, for an x:yaspect ratio, no matter how big or small the image is, if the width is divided into x units of equal length andthe height is measured using this same length unit, the height will be measured to be y units. For example,consider a group of images, all with an aspect ratio of 16:9. One image is 16 inches wide and 9 incheshigh. Another image is 16 centimetres wide and 9 centimetres high. A third is 8 yards wide and 4.5 yardshigh.The most common aspect ratios used today in the presentation of films in movie theatres are 1.85:1(50:27) and 2.39:1 (43:18).Two common video graphic aspect ratios are 4:3 (1.3:1), the universal videoformat of the 20th century and ; 16:9 (1.7:1), universal for high-definition television and European digitaltelevision. Other cinema and video aspect ratios exist, but are used infrequently. As of 2010, nominally21:9 (2.3) aspect TVs have been introduced by Philips and as "cinema" displays, though the resolution ismore precisely 2560 / 1080 = 64 / 27 = 2.37 (2.370 exactly), and the aspect ratio is not standardized inHDTV.With television, DVD and Blu-ray, converting formats of unequal ratios is achieved by either: enlarging theoriginal image (by the same factor in both directions) to fill the receiving formats display area and cuttingoff any excess picture information, by adding horizontal mattes or vertical mattes to retain the originalformats aspect ratio, or by stretching the image to fill the receiving formats ratio, by scaling by differentfactors in both directions, possibly scaling by a different factor in the centre and at the edges.
BTec Level 3Extended Diploma in Creative Media ProductionHA1 - Technical File – File FormatsGIF - Graphics Interchange Format is a bitmap image format that was introduced by CompuServe in 1987and has since come into widespread usage on the internet due to its wide support and portability. Theformat supports up to 8 bits per pixel thus allowing a single image to reference a palette of up to 256 distinctcolours. The colours are chosen from the 24-bit RGB colour space. It also supports animations and allows aseparate palette of 256 colours for each frame. The colour limitation makes the GIF format unsuitable forreproducing colour photographs and other images with continuous colour, but it is well-suited for simplerimages such as graphics or logos with solid areas of colour.JPEG - JPEG is a commonly used method of compression for images. The degree of compression can beadjusted, allowing a selectable trade off between storage size and image quality. JPEG typically achieves10:1 compression with little perceptible loss in image quality.TIFF -Tagged Image File Format is a file format for storing images, popular among graphic artists, thepublishing industry, and both amateur and professional photographers in general. As of 2009, it is under thecontrol of Adobe Systems. Originally created by the company Aldus for use with what was then called‘desktop publishing’, the TIFF format is widely supported by image-manipulation applications, by publishingand page layout applications, by scanning, faxing, word processing, optical character recognition and otherapplicationsPSD - Photoshops native format, stores an image with support for most imaging options available inPhotoshop. These include layers with masks, colour spaces, ICC profiles, transparency, text, alphachannels and spot colours, clipping paths, and duotone settings.PDF - Portable Document Format (PDF) is an open standard for document exchange. This file format,created by Adobe Systems in 1993, is used for representing documents in a manner independent ofapplication software, hardware, and operating systems. Each PDF file encapsulates a complete descriptionof a fixed-layout flat document, including the text, fonts, graphics, and other information needed to display it.EPS - Encapsulated PostScript files are more or less self-contained, reasonably predictable PostScriptdocuments that describe an image or drawing and can be placed within another PostScript document. EPSfiles also frequently include a preview picture of the content, for on-screen display.
BTec Level 3Extended Diploma in Creative Media ProductionHA1 - Technical File – Colour ModelsRGB - The RGB colour model is an additive colour model in which red, green, and blue light is addedtogether in various ways to reproduce a broad array of colors. The name of the model comes from theinitials of the three additive primary colors, red, green, and blue.The main purpose of the RGB colour model is for the sensing, representation, and display of imagesin electronic systems, such as televisions and computers, though it has also been used inconventional photography. Before the electronic age, the RGB colour model already had a solid theorybehind it, based in human perception of colors.CYMK - The CMYK colour model (process colour, four colour) is a subtractive colour model, used incolour printing, and is also used to describe the printing process itself. CMYK refers to the four inksused in some colour printing: cyan, magenta, yellow, and key (black). Though it varies by print house,press operator, press manufacturer and press run, ink is typically applied in the order of theabbreviation.
BTec Level 3Extended Diploma in Creative Media ProductionHA1 - Technical File – Adobe PhotoshopAdobe Photoshop is a graphics editing program developed and published by Adobe Systems Incorporated.Adobes 2003 "Creative Suite" rebranding led to Adobe Photoshop 8s renaming to Adobe Photoshop CS.Thus, Adobe Photoshop CS5 is the 12th major release of Adobe Photoshop. The CS rebranding alsoresulted in Adobe offering numerous software packages containing multiple Adobe programs for a reducedprice. Adobe Photoshop is released in two editions: Adobe Photoshop, and Adobe Photoshop Extended,with the Extended having extra 3D image creation, motion graphics editing, and advanced image analysisfeatures. Adobe Photoshop Extended is included in all of Adobes Creative Suite offerings except DesignStandard, which includes the Adobe Photoshop edition. Alongside Photoshop and Photoshop Extended,Adobe also publishes Photoshop Elements and Photoshop Lightroom, collectively called "The AdobePhotoshop Family". In 2008, Adobe released Adobe Photoshop Express, a free web-based image editingtool to edit photos directly on blogs and social networking sites; in 2011 a version was released for theAndroid operating system and the iOS operating system. Adobe only supports Windows and Macintoshversions of Photoshop, but using Photoshop CS5 can run well on Linux.
BTec Level 3Extended Diploma in Creative Media ProductionHA1 - Technical File – Adobe IllustratorAdobe Illustrator is a vector graphics editor developed and marketed byAdobe Systems. Illustrator is similar in scope, intended market, andfunctionality to its competitors, CorelDraw, Xara Designer Pro andMacromedia FreeHand. The latest version, Illustrator CS5, is thefifteenth generation in the product line.
BTec Level 3Extended Diploma in Creative Media ProductionHA1 - Technical File – Adobe InDesignAdobe InDesign is a software application produced by Adobe Systems. It can be used tocreate works such as posters, flyers, brochures, magazines, newspapers and books.InDesign can also publish content suitable for tablet devices in conjunction with AdobeDigital Publishing Suite. Graphic designers and production artists are the principal users,creating and laying out periodical publications, posters, and print media. It also supportsexport to EPUB and SWF formats to create digital publications, and content suitable forconsumption on tablet computer devices. The Adobe In Copy word processor uses thesame formatting engine as InDesign.
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