Chapter 3: Images PDF

Chapter 3: Images © 2011 The McGraw-Hill Companies, Inc. All rights reserved  Lesson Outcome Creation of multimedia images Creation of still images Colors and palettes in multimedia Image file types used in multimedia © 2011 The McGraw-Hill...

Chapter 3: Images © 2011 The McGraw-Hill Companies, Inc. All rights reserved  Lesson Outcome Creation of multimedia images Creation of still images Colors and palettes in multimedia Image file types used in multimedia © 2011 The McGraw-Hill Companies, Inc. All rights reserved  Creation of Still Images (continued) Types of still images: Bitmaps (paint graphics)/ raster images Vector-drawn (“drawn” graphics) Bitmap editors- “painting” programs Vector editors- “drawing” programs © 2011 The McGraw-Hill Companies, Inc. All rights reserved  Bitmaps Vector-drawn graphics Usage Photo-realistic images Graphic shapes that can be Complex drawings (fine mathematically expressed in detail) angles, coordinates, distances e.g boxes, circles Appearance Depends on display resolution, graphics hardware, monitor capabilities File format Various Cross Able platform Memory more less space File size bigger smaller Download slower faster time Drawing time © 2011 The McGraw-Hill Companies, Inc. All rights reserved  Bitmaps Vector-drawn graphics photorealistic images Able Cannot plug-in for Web-based No Yes display? Scalability Difficult Easy Bitmaps can be converted to vector images using autotracing. REFER To this Video.. https://www.youtube.com/watch?v=p2thSkOa_Xg © 2011 The McGraw-Hill Companies, Inc. All rights reserved  Creation of Still Images (cont’) Bitmaps – Bit: binary on/off, true (1)/false (2) – Map: 2D matrix of bits – Bitmap: data matrix describing individual dots of image (pixels/pels) © 2011 The McGraw-Hill Companies, Inc. All rights reserved  Creation of Still Images (cont’) 24 bits depth. Dithered to 8 bits. Dithered to 8 bits. Dithered to 4 bits. Millions of colors. Adaptive palette Macintosh palette 16 colors. of 256 colors. of 256 colors. Available binary Combinations for Describing a Color Dithered to 8-bit Dithered to 4-bit Dithered to 1-bit. gray-scale. gray-scale. Two colors, black 256 shades of gray. 16 shades of gray. and white. © 2011 The McGraw-Hill Companies, Inc. All rights reserved  Creation of Still Images (cont’) Bitmap sources: – From scratch using paint/drawing program – Industry-standard: – Adobe’s Photoshop, Illustrator – Corel’s Painter, CorelDraw – Screen capture – clip art galleries – bitmap software – Scanning images – Download © 2011 The McGraw-Hill Companies, Inc. All rights reserved  Creation of Still Images (cont’) Using clip art galleries A page of thumbnails showing the content of various royalty-free Photodisc collections from Getty Images © 2011 The McGraw-Hill Companies, Inc. All rights reserved  Creation of Still Images (cont’) Image editing programs enable user: – Enhance, make composite images. – Alter, distort images. – Add, delete elements. – Morph (manipulate still images to create animated transformations). © 2011 The McGraw-Hill Companies, Inc. All rights reserved  Creation of Still Images (cont’) Morphing software was used to seamlessly transform the images of 16 kindergartners. When a sound track of music and voices was added to the four-minute piece, it made a compelling video about how similar children are to each other. © 2011 The McGraw-Hill Companies, Inc. All rights reserved  Creation of Still Images (cont’) Users can scan images from conventional sources and make necessary alterations, manipulations. Exposure from Alien Skin allows users to manipulate bitmapped images. Here a digital color image has been processed to look like it came from a darkroom. © 2011 The McGraw-Hill Companies, Inc. All rights reserved  Creation of Still Images (cont’) Vector-drawn images used in the following areas: – Computer-aided design (CAD) programs – Graphic artists designing for the print media – 3D animation programs – Applications requiring drawing of graphic shapes © 2011 The McGraw-Hill Companies, Inc. All rights reserved  Creation of Still Images (cont’) Drawing software such as Adobe Illustrator can save vector graphics in SVG format. © 2011 The McGraw-Hill Companies, Inc. All rights reserved  Creation of Still Images (cont’) How vector-drawn images work – Vector: a line that is described by the location of its two endpoints. – Vector drawing makes use of Cartesian coordinates. – Cartesian coordinates are numbers that describe a point in 2 or 3D space as the intersection of X, Y, and Z axes. © 2011 The McGraw-Hill Companies, Inc. All rights reserved  Creation of Still Images (cont’) 3D drawing and rendering – 3D animation tools – Features of a 3D application – Panorama © 2011 The McGraw-Hill Companies, Inc. All rights reserved  Creation of Still Images (cont’) 3D animation, drawing,rendering tools: – Daz3D – Form*Z – NewTek′s Lightwave – Autodesk’s Maya – Google’s SketchUp 3-D applications provide x, y, and z axes and adjustable perspective views. © 2011 The McGraw-Hill Companies, Inc. All rights reserved  Creation of Still Images (cont’) Features of a 3D application – Modeling - Placing elements into 3D space – Extrusion – shape of plane surface extends some distance – Lathing - profile of shape rotated around defined axis © 2011 The McGraw-Hill Companies, Inc. All rights reserved  Creation of Still Images (cont’) - Rendering: Use of intricate algorithms to apply user-specified effects © 2011 The McGraw-Hill Companies, Inc. All rights reserved  Creation of Still Images (cont’) Panoramas – Panoramic images are created by 1. Stitching together a sequence of photos around a circle 2. adjusting them into a single seamless bitmap © 2011 The McGraw-Hill Companies, Inc. All rights reserved © 2011 The McGraw-Hill Companies, Inc. All rights reserved  Colors and Palettes in Multimedia Understanding natural light and color Color palettes Color pickers allow you to select a color using one or more different models of color space. © 2011 The McGraw-Hill Companies, Inc. All rights reserved  Colors and Palettes in Multimedia (cont’) Understanding natural light, color – No light, no color – Color: property possessed by an object of producing different sensations on the eye as a result of the way it reflects or emits light – 2 basic methods of making color: – Additive – Subtractive © 2011 The McGraw-Hill Companies, Inc. All rights reserved  Colors and Palettes in Multimedia (cont’) – Additive Color – Color created by combining colored light sources in 3 primary colors: – Red RGB – Green – Blue – Usage: – Cathode ray tube (CRT): TV – Liquid crystal (LCD) – Plasma displays © 2011 The McGraw-Hill Companies, Inc. All rights reserved © 2011 The McGraw-Hill Companies, Inc. All rights reserved  Colors and Palettes in Multimedia (cont’) Subtractive color – color created by combining colored media such as paints or ink – The colored media absorb (or subtract) some parts of the color spectrum of light and reflect the others back to the eye – Usage: color in printing – printed page consists of tiny halftone dots of 3 primary colors: cyan, magenta, yellow (CMY) © 2011 The McGraw-Hill Companies, Inc. All rights reserved  Colors and Palettes in Multimedia (cont’) Monitor-specific colors – Colors used according to the target audience’s monitor specifications. – preferred monitor resolution: 800 x 600 pixels. – preferred color depth: 32 bits. © 2011 The McGraw-Hill Companies, Inc. All rights reserved  Colors and Palettes in Multimedia (cont’) Models used to specify color in computer terms: – RGB model – 24-bit methodology – Color specified in terms of RGB values ranging from 0-255 – Hexadecimal pair – Used during early development of browsers – 2 hexadecimal no, written in a scale of 16 no and letters in the range “0123456789ABCDEF” – E.g: in HTML, pure green= #00FF00 (1st pair:#00 = no red, 2nd pair:#FF=pure green, last pair:#00= no blue) © 2011 The McGraw-Hill Companies, Inc. All rights reserved  – HSB (hue, saturation, brightness) and HSL (hue, saturation, lightness) models – hue/color: angle, 0-360 degrees on color wheel - saturation, brightness, lightness: % - Saturation: intensity of color - 100% saturation: pure color - 0%: white/black/gray - Lightness/brightness: % of black/white mixed with a color - 100% lightness: white - 0%: black - 50%: pure color © 2011 The McGraw-Hill Companies, Inc. All rights reserved © 2011 The McGraw-Hill Companies, Inc. All rights reserved  – CIE – Describes color values in terms of frequency, saturation, illuminance – Resembles how human beings perceive color – Cons: certain devices e.g scanner unable to replicate the process – YIQ, YUV: developed for broadcast TV – YCC: photoCD images © 2011 The McGraw-Hill Companies, Inc. All rights reserved  Colors and Palettes in Multimedia (cont’) Color palettes – mathematical tables that define color of pixels displayed on screen – called CLUTs (color lookup tables) on Mac – most common palettes: 1, 4, 8, 16, 24-bit deep © 2011 The McGraw-Hill Companies, Inc. All rights reserved  Colors and Palettes in Multimedia (cont’) Dithering: – process where color value of each pixel changed to the closest matching color value in target palette – Method: mathematical algorithm © 2011 The McGraw-Hill Companies, Inc. All rights reserved  Image File Types Used in Multimedia Macintosh formats Windows formats Cross-platform formats © 2011 The McGraw-Hill Companies, Inc. All rights reserved  Image File Types Used in Multimedia (cont’) Macintosh formats – most common: PICT – complicated, versatile – by Apple – can be imported, exported by almost every image application on Mac – In PICT file, both vector-drawn objects and bitmaps can reside side-by-side © 2011 The McGraw-Hill Companies, Inc. All rights reserved  Image File Types Used in Multimedia (cont’) Windows formats – most common: DIB (device independent bitmaps) aka BMP – Bitmap formats used most often by Windows developers: BMP - A Windows bitmap file TIFF (Tagged Interchange File Format) - Extensively used in DTP packages PCX - Used by MS-DOS paint software © 2011 The McGraw-Hill Companies, Inc. All rights reserved  Image File Types Used in Multimedia (cont’) Cross-platform formats JPEG, GIF, PNG Web Adobe PDF Manages multimedia content (Portable Document Format) PSD, AI, CDR, DXF Proprietary formats used by applications IGS/IGES Standard for transferring CAD (Initial Graphics Exchange Standard) drawings © 2011 The McGraw-Hill Companies, Inc. All rights reserved  Summary computer generates still images as bitmaps and vector-drawn images. Images can be incorporated in multimedia using clip art, bitmap software, capturing, editing, scanning images. Creating 3D images involves modeling, extruding, lathing, shading, rendering. Color is one of the most vital components of multimedia. © 2011 The McGraw-Hill Companies, Inc. All rights reserved