Chapter 9

JPEG

- 16.8 million colors but no transparency - A format for compressing image files. - Photographs

Enhanced Definition Television (EDTV)

- A common name for a particular subset of the DTV (Digital Television) standards, but is considered to be specifically a part of the HDTV format.

Raster Image

- A dot matrix data structure, representing a generally rectangular grid of pixels, or points of color, viewable via a monitor, paper, or other display medium. - Made up of pixels

TIFF

- A format for image files - Uncompressed

GIF

- A lossless format for image files that supports both animated and static images. - Offers 256 colors and transparency - Logos and other images with lines and solid blocks of color

Interlaced Scanning

- A method of raster scanning - Each frame of an image is capture in two parts and transmitted separate - Happens so quickly that you don't notice

Sequential Color and Memory (SECAM)

- A set of analog television standards - Developed in France

Phase Alternating Line (PAL)

- A set of analog television standards - Developed in Germany

National Television Standards Committee (NTSC)

- A set of analog television standards - Developed in US

Advanced Television Systems Committee (ASTC)

- A set of standards for digital television transmission over terrestrial, cable, and satellite networks. - Brings better graphics - SDTV - EDTV - HDTV

Digital Video Broadcasting (DVB)

- A set of standards that define digital broadcasting using existing satellite, cable, and terrestrial infrastructures.

Still Image

- A single static image

High-Definition Television (HDTV)

- A television system providing an image resolution that is of substantially higher resolution than that of standard-definition television

Standard Definition Television (SDTV)

- A television system that uses a resolution that is not considered to be either high-definition television or enhanced-definition television

Image

- A two- or three-dimensional representation of a person, animal, object, or scene in the natural world

Color Space

- An abstract mathematical model which simply describes the range of colors as tuples of numbers, typically as 3 or 4 values or color components

Graphics

- Any type of visual presentation that can be displayed on a physical surface such as a sheet of paper, wall, poster, blackboard, or computer monitor

Two common methods used to digitally encode and display computer graphics

- Bitmap or Raster imaging - Vector imaging

Because digital images are recorded numerically as binary data, they (blah)

- Cannot be directly touched or viewed

Resampling

- Changes the size of a raster image by increasing or decreasing the image's pixel count

Digital Television (DTV)

- Compatible with computer and Internet-based systems and services - More stations can be broadcast in the same viewing area - Higher quality

Additive Color Mixing

- Computer and television displays emit light - White light is formed by adding all the colors of the rainbow together - In the absence of light, the image or pixels on an electronic display appear black

Progressive Scanning

- Consecutively scanning the lines of the picture from top to bottom - Helps to combat eyestrain on computer monitors

CMYK Color Space

- Cyan - Magneta - Yellow - Used for color printing

Native Resolution

- Fixed pixel dimensions

Vector Graphic

- Graphics that can be scaled up or down without losing any picture clarity

In analog photography, the negative is used to (blah).

- Make photographic prints

Compression

- Makes files with a lot of information to be smaller - Lossless for efficient ways to store with losing info - Lossy for reducing file size by getting rid of data that is not needed

PNG

- Offers 16.8 million colors and transparency - Can choose to use fewer colors to save file space (PNG 8) - Common for many images - Not supported by all web browsers

Field/Frame

- One complete scanning pass of either the odd or even scan line

A digital device or computer is required to render a binary image for (blah)

- Output to display screen or a printer

Moving Image

- Personal computers - TV - Movies - Games - Phones - GPS

Cropping

- Photo editing technique used to delete portions of an image in order to enhance the focus of a main subject or improve composition

Subtractive Color Mixing

- Printing relies on it - The pigments absorb colors, so when you put all the colors together, you theoretically get black: each pigment absorbs a different range of light, so no light is reflected back to your eyes

Computer Graphics

- Processes in which pictorial data is encoded and displayed by computers and digital devices - Two kinds which are graphics and images

RGB Color Space

- Red - Green - Blue - Used in multimedia design

Color Depth

- Refers to how many different shades of color a computer or device can utilize when capturing or rendering a digital image

Pixel

- Short for picture element - A square area of light representing a single point in a raster image

Anti-Aliasing

- Smooths out the edges of jagged type by blending the color transition points

Resolution

- Term most often used to describe the image quality of a raster image - Refers to the size and quantity of the pixels the image contains

Frame Rate

- The frequency at which frames in a television picture, film, or video sequence are displayed.

The more pixels you have in a given area, the more information you have, and (blah)

- The higher the resolution of the image

Aliasing

- The jagged, or saw-toothed appearance of curved or diagonal lines on a low-resolution monitor.

Refresh Rate

- The number of complete scanning cycles per second and is measured in Hertz, a unit of frequency equal to one cycle per second

Image Optimization

- The smaller the image file, the less time it takes to download from the web - Practice that can help search engines find and correctly index your site, producing listings of your site in search results relevant to your material

Pixel Count

- The total number of pixels in a raster matrix - Determined by multiplying the number of pixels across a digital image by the number of pixels high

Scaling

- Upscale or downscale a raster image - Upscaling results in a noticeable loss of image quality - Downscaling has no issue