1 / 20

EDU3130 Simple Graphic Manipulations I

EDU3130 Simple Graphic Manipulations I Rosanna Chan Multimedia Elements Multimedia elements include: Digital Video Digital Audio Text abvdefghij Klmnopqrst uvwxyz Multimedia Graphics Animation Multimedia Elements Graphics

emily
Download Presentation

EDU3130 Simple Graphic Manipulations I

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript


  1. EDU3130Simple Graphic Manipulations I Rosanna Chan

  2. Multimedia Elements • Multimedia elements include: Digital Video Digital Audio Text abvdefghij Klmnopqrst uvwxyz Multimedia Graphics Animation UIT - Multimedia Production

  3. Multimedia ElementsGraphics • Graphics is a digital representation of non-text information such as a drawing, chart, or photograph. • It is also called a digital picture or image, and contains no movement or animation • 3 fundamental characteristics of color • Hue (色調) • Related to the wavelength of light • Lightness (亮度) • Related to the amplitude of light • Saturation (彩度) • Related to the purity of light UIT - Multimedia Production

  4. Multimedia ElementsGraphics Pixel • A pixel is the smallest unit of programmable color on a computer display or in a computer image • Every computer graphic is made up of a grid of pixels • There are two types of graphics • Bitmap graphics • Vector graphics UIT - Multimedia Production

  5. Multimedia ElementsGraphics Bitmap Graphics • Bitmap is a representation of a graphics image • Consists of rows and columns of dots • The value of each dot (whether it is filled in or not) is stored in one or more bits of data • Simple monochrome images use one bit to represent each dot UIT - Multimedia Production

  6. Multimedia ElementsGraphics Bitmap Graphics • The more bits used to represent a dot, the more colors and shades of gray that can be represented: 1-bit image, 2 color: black or white 8-bit image, 256 colors (28=256) 24-bit image, 16777216 colors (true color) UIT - Multimedia Production

  7. Multimedia ElementsGraphics Resolution • Determines how sharply the image is represented • Expressed in dot per inch (dpi), or simply by the number of rows and columns, such as 640 by 480 • Bitmap graphics suffer distortion in image quality when being scaled up, this does not happen in case of vector graphics Vector graphic Bitmap graphic UIT - Multimedia Production

  8. Multimedia ElementsGraphics Vector Graphics • Vector graphics are based on mathematical formulas that represent curves and lines • Very smooth looking and can easily be resized without loss of image quality UIT - Multimedia Production

  9. Multimedia ElementsGraphics Formats • A format is a standard specifying how the data is arranged • For bitmap graphics • BMP • GIF • JPEG • For vector graphics • EPS • WMF UIT - Multimedia Production

  10. Multimedia ElementsGraphics Formats • BMP (.bmp) • Microsoft's native graphic file format • GIF (Graphic Image Format) (.gif) • Only supports 256 colors; therefore the file sizes can be kept small. GIF works best when the number of colors within an image is small • JPEG (Joint Photographic Experts Group) (.jpg) • Supports millions and allows for graphic compression. Most people use JPEG for Web graphics that contain a multitude of colors and gradations - like photographic images • EPS (Encapsulated Postscript) (.eps) • For image attached within a PostScript language document • WMF (Windows Metafile Format) (.wmf) • For exchanging graphics between Microsoft applications such as clipart in Microsoft Office UIT - Multimedia Production

  11. Multimedia ElementsGraphics Vector Graphics • An example of vector graphic is the clipart in MS PowerPoint • When you enlarge a clipart image, it will not distort UIT - Multimedia Production

  12. Multimedia ElementsGraphics GIF versus JPEG • When the number of color of an image is large, JPEG performs better JPEG format, 6k bytes GIF format, 13.5k bytes UIT - Multimedia Production

  13. Multimedia ElementsGraphics GIF versus JPEG • When the number of color of an image is small, GIF performs better JPEG, 5.4 bytes GIF, 1.5k bytes UIT - Multimedia Production

  14. Multimedia ElementsComputer-based Animation • Literally, “To animate something” means “to bring it to life” • An animation covers all changes that have a visual effect (e.g. position, color) • Displaying a series of still graphics creates an animation, which is cause by the illusion of motion Techniques Used • Input Process • Drawings must be digitized (e.g. scanned) to create key frames, where the entities being animated are at extreme or characteristic positions. • The drawing may need to be carefully post-processed (e.g. filtering) in order to clean up any glitches arises from the input process UIT - Multimedia Production

  15. Multimedia ElementsComputer-based Animation Techniques Used • In-between Process • Intermediate frames are insert between key frames • Interpolation methods is used • The computer obtain only the beginning and end positions, and fill-in the intermediate positions • Color changes is achieved by the Color-Look-Up Table (CLUT) of the graphic memory Frames Interpolation CLUT UIT - Multimedia Production

  16. Multimedia ElementsComputer-based Animation Methods of Creating Animation • Digital animation is based on the flipbook approach – a sequence of images is compressed and then played back to convey a sense of motion • The playback rate is the number of images displayed per second when the animation is being viewed • To effectively create the illusion of motion, the playback rate of animation must be at least 24 frames per second • An image is said to Flicker when the illusion of motion fails and the animation appears as a rapid sequence of still images instead of a fluid object in motion UIT - Multimedia Production

  17. Multimedia ElementsComputer-based Animation Frame-Based Animation • Also called cell animation • Key frames that describe key events in the timeline of the animation are created on cells or frames • Tweening (the process of filling in the frames between the key frames) is used to make the animation appear smooth • Morphing is a special technique that uses frames to create the illusion of one object changing into another (also called shape-tweening) UIT - Multimedia Production

  18. Multimedia ElementsComputer-based Animation Path-Based Animation • Also called vector animation • Creates animated objects by following an object’s transition over a line or vector • The artist creates only one drawing and a path, then the computer manipulates this object by drawing the frames as the object travels over the path • Computational animation allows an object to be moved across a screen by varying its x and y coordinates UIT - Multimedia Production

  19. Multimedia ElementsComputer-based Animation Script-Based Animation • Script-based animation is created using programming languages • LINGO • The programming language included in Macromedia Director • Is an object-oriented scripting language that extends Director’s build-in capability • JAVA • Java applets can be used to create advanced animated objects • Java enable computational animation: it can react to external input • Examples: http://fractal.leet.net.au/page.php?page=funkyapplets UIT - Multimedia Production

  20. Multimedia ElementsComputer-based Animation Animated GIFs • Animated GIFs are a special kind of GIF file known as GIF89a • An animated GIF file stores multiple images as separate blocks within a single GIF file • When being viewed on the Web, the multiple images are streamed (played back one at a time) • Streaming: the viewer does not have to wait for the entire GIF to be downloaded before it begins running on a Web page UIT - Multimedia Production

More Related