Animation & Video

ACS 352

Animation

• Animation can describe two-dimensional (2D) or three-dimensional (3D) objects, processes, or phenomena in ways not possible in the "real world".

• Animation can describe events or processes that cannot be easily videotaped such as global networks, biochemical processes, or prehistoric ecological systems.

Animation

• Animation may be better suited than video for portraying sensitive or complex events.– For example, showing a car part assembly

process in animation provides a clearer, more focused view than videotaping the process with all of the other parts an associated dirt and grime in the way.

Computer Art

• Artists use a variety of computer technologies to produce images and humanoids. – 3D modeling packages– Drawing programs– Image processing applications– CAD Software

Humanoids

• Perceptual Science Laboratory

• Web Anchors – Ananova

• MIT Media Lab

• Animations - Gloria

Entertainment

• Final Fantasy

Morphing

• Morphing is the process of smoothly dissolving between two images, so that one appears to become the other.

• One image is transformed gradually into another, by physically warping prominent features of the first image onto prominent features of the second. At the same time pixel colors are cross faded between them

Morphing Examples

• Presidents

• Presidents

Video

• Video technology springs from television technology.

• The United States established standards that defined how television works.

• The National Television Standard Committee (NTSC) developed specifications that determined the number of still images, or frames, that appeared per second on television screens.

NTSC

• 30 frames per second (fps) for monochrome television

• 29.97 interlaced fps for color television with a resolution of 525 lines.

• Each frame is interlaced-odd lines of the frame appear in one pass and even lines appear in another pass

Analog Video formats

• Consumer– VHS, 8mm

• High-end consumer / Industrial– S-VHS, Hi-8mm, 3/4 inch and 3/4 inch SP

Umatic

• Professional– Betacam and Betacam SP, MII, 1-inch C.

Digital Video

• Refers to the capturing, manipulation and storage of video in digital formats.

• A digital video (DV) camcorder, for example, is a video camera that captures and stores images on a digital medium.

How Video is Digitized

• Capture the Video– Video and audio come in from a video source,

either a camera or VCR, to the audio and video digitizer cards inside a computer. On some systems both the audio and video digitizing functions are on one card.

Sampling

• Using a process called Sampling, the analog-to-digital (A/D) converters on the cards process the analog video and audio signals into digital data streams.

• Sampling is the process that changes the video and audio signals into a binary data structure of 1's and 0's that exists in all computer media

Digital Video

• Although the capture formats are important within desktop multimedia the playback of digital video is largely limited to a few key formats:– PC: AVI ,MPEG, ASF, RM– MAC: Quicktime Movies

Multimedia - Video

• There are three basic ways to incorporate video into a multimedia application:– Analog pass-through

• which includes an analog video source (laser disc or a video cassette recorder) and an overlay board.

Multimedia - Video

• Softvideo (software based video)• does not require any specialized hardware to display

digital video.

• Three common softvideo solutions are:– Video for windows (AVI)

– QuickTime for Macs and PCs.

– Streaming Media (ASF, RM)

Streaming

• Streaming is a technique that allows users to play content while they are receiving it rather than waiting for an entire file to be down loaded. – Real Networks

• Real Player

• Real Producer

Multimedia - Video

• Hardvideo (hardware assisted video) requires specialized hardware (video CODEC boards) to display digital video. The advantage of hardvideo is that offers high quality video. – the resolution is higher (frame size)– the video motion is smoother (high frame rates

per second - 30 fps)– almost transparent scalability.

Standards

• Today's multimedia typically uses a screen pixel ratio of 4:3 – 640x480, 1024x768, etc

• The new High Definition Television (HDTV) standard specifies a ratio of 16:9– much wider than tall.

Quality of Video

• Each second of video can require 27 MB of data.– Video Requirements =

• 30 (frames) x [640 x 480] (pixels per video frame)

x 3 (bytes per pixel for 24-bit color) = 27,648,000 bytes per second

• Audio Requirements =44,100 (sample quality) x 2 (for stereo) x 2 (16-bit sample size) = 176,400 bytes per second

Compression

• To overcome the problems caused by the massive size of video files, vendors and industry groups have devised various methods that compress data.

• These methods delete redundant information from images, store them in short-hand form, and then expand them for display and use.

Compression

• Necessary for the pictures you want to display - both still and video - so they can be stored, processed, and moved around the computer fast enough to produce good interactive performance.

Lossless vs. Lossy Compression

• LosslessThe exact original data can be recovered from the compressed file.No data is lost or discarded.LossySome information is lost when the data is reconstructed.Throw away some of the data in an image in order to achieve better compression.

CODECs

• These methods, called CODECs for compression/decompression, vary in how, and how much, data they compress and in their suitability for various applications.

Codec

• Indeo: A codec (compression/decompression technology) for computer video developed by Intel Corporation.– Although it is a software -only codec, Indeo is

based on the DVI, which is a hardware only codec.

• Competing video standards include Cinepak and MPEG.

MPEG

• MPEG generally produces better-quality video than competing formats, such as Video for Windows, Indeo and QuickTime. MPEG files can be decoded by special hardware or by software.

• MPEG achieves high compression rate by storing only the changes from one frame to another, instead of each entire frame.

• lossy compression

Video for Windows

• Video for Windows was released in 1992 by Microsoft.

• Video for Windows is both – an architecture – and applications suite

Video for Windows - Architecture

– Video for Windows provides inbound and outbound interfaces.

• Inbound interfaces ensures that various multimedia components work effectively together. These also provide a standard interface for various codecs such as Cinepak and Indeo.

• As an outbound architecture Video for Windows provides two application programming interfaces (API) for use in integrating video into applications.

– MCI (Media Control Interface)– OLE (Object Linking and embedding )

Video for Windows - Architecture

• MCI– a high-level API developed by Microsoft and

IBM for controlling multimedia devices, such as CD-ROM players and audio controllers.

• OLE– allows the use of multimedia elements in

business applications.

Video for Windows - AVI

• AVI (Audio/Video interleaved) – The file format used by Video for Windows

which interleaves alternate blocks of video and audio.

Video Standards

TV & Digital Video Standards

Things to consider

• The inclusion of video sequences could significantly improve the user's consistency in the decision making process (Vila, et all, 1995).

• Video can be especially good for capturing personal information in interviews.

• Video can be used in documentaries to describe theories, present evidence, and support conclusions.

Things to consider

• Video can be used to teach by example and show processes that are difficult to describe in text.

• Depending on the subject matter, video can more easily cross linguistic and cultural boundaries.

• Video can be used to communicate to a wider audience than text or speech can reach.

Things to consider

• Video can also be an effective means of communicating to hearing or learning impaired people.

• To establish visual orientation, present video in three-shot sequences (long, medium, and close-up).

• To grab student's attention and imply that something is important, use close-up shots.

Shooting Video

• The eye focuses on lighted instead of dark areas and movement instead of static images.

• Always consider the hiring of professional videographers or video production house to shoot the video sequences for you.

• Use subdued colors for all of your set's backgrounds and talent's attire.

Shooting Video

• Highly saturated colors such as red or blue will reduce the overall quality of a digitized

• Keep your camera movements smooth and stay away from too many pans or zooms. If you will be digitizing your video at 15 frames per second (fps) excessive camera movements may cause the shot to look jittery.

Examples