Lesson 3

Layering

compiling multiple pictures or objects together into one image a. Layers can be turned on or off b. Elements can be colored, layered, and resized individually

Cloning

copying part of an image and using it to replace unwanted parts of the image.

Portability

ease at which files are opened, modified, and viewed on computers using different operating systems, software and browsers.

Gradients

filling an object with a smooth transition from one color to another.

Resolution independent

regardless of how much the image is enlarged or reduced, the image definition and quality remain the same

Aspect Ratio -

relationship of an object's width to its height

Cropping

removing a part of an image a. The original image retains the same file size b. The cropped image can be saved as a new object

Transparency

removing the background color of a raster image making it "see-through" in order to allow the image to blend in with its background.

Lossy

some data is lost during compression.

Image Editing

Aspect Ratio Cloning Cropping Filters Gradients Layering Patterns and Textures Rotating Transparency

IFF - Tagged Image File Format

Characteristics (i) Does not support animation or transparency (ii) Available in compressed (lossless) and uncompressed formats (iii) Supports up 16 M colors Commonly used for: (i) Storing raw bitmap data by some programs and devices such as scanners (ii) High resolution printing (iii) Desktop publishing images (iv) Storage container for faxes and other digital images

GIF - Graphics Interchange Format

Characteristics (i) Standard format on web for animation (ii) Supports transparency (iii) Uses lossless compression (iv) Supports 256 colors Used for:Clip art, animations, icons, logos (ii) Simple diagrams, line drawings (iii) Graphics with large blocks of a single color (iv) Graphics with transparent areas (v) Graphics displayed on computer screens

PNG - Portable Network Graphic

Characteristics (i) Supports transparency (ii) Uses lossless compression (iii) Supports several different color depths; including 256 colors and 16 million colors Commonly used for: (i) Replacing GIF and TIFF images (ii) Online viewing of images

BMP - Bitmap (Windows)

Characteristics: (i) Does not support animation or transparency (ii) Uncompressed (iii) Supports 256 colors (iv) Large file size; not well suited for transfer across the Internet or print publications Commonly used for: (i) Editing raster graphics (ii) Creating icons and wallpaper

Types of Images

1. Clip Art - premade graphics that are available online and in many software packages; may be vector or raster 2. Photographs - raster images that contain millions of colors. 3. Art Work - computer created drawing or painting; may be raster or vector

Common Vector File Formats

Disadvantages to vector graphics Lower color quality than bitmap images Not good for photographic images NOTE: Meta graphic formats can contain both vector and raster data. i. AI - Adobe Illustrator ii. CDR - Corel Draw iii. DXF - AutoCAD iv. EPS - Encapsulated Postscript (meta graphic) v. SVG - Scalable Vector Graphics vi. WMF - Windows Metafile, common format for

DPI

Images that will be displayed on a monitor or screen can have a lower resolution because most monitors/screens do not support very high resolutions. - dots per inch a. The number of dots of ink or toner per inch on a printed image. b. The lower the DPI the less detailed the image. c. Images that will be printed need a higher resolution in order to print clearly without pixelation or blurriness.

JPEG - Joint Photographic Experts Group

JPEG - Joint Photographic Experts Group Characteristics (i) Does not support animation (ii) Does not support transparency (iii) Uses lossy compression (iv) Supports 16 M colors (v) High quality; but larger file size than gif Commonly used for: (i!)Desktop publishing images (ii) Photographs and natural artwork (iii) Scanned images (iv) Emailing photographs (v) Digital camera photographs

small file sizes

Small file sizes - easily transferred over the Internet

Factors that Affect Graphic Choice

a. Color depth refers to the number of colors per pixel that can be displayed in an image. b. Compression refers to how an image is saved in order to reduce the file size. i. The greater the compression, the lower the quality of the image.

Patterns and Textures a. Patterns are raster graphics applied as a fill b. Textures are used to create filters and backgrounds

a. Patterns are raster graphics applied as a fill b. Textures are used to create filters and backgrounds

Raster Graphics

also called bitmap graphics. a. Images composed of grids of pixels that have a fixed resolution (number of pixels per inch) and cannot be resized without losing image quality, are edited in print programs.

Graphics

anything on a page that is not actual text, from simple line drawings to fully active images found on the World Wide Web.

Vector Graphics

formulas that define lines, shapes and curves. Characteristics i.Shapes can be edited by moving points called nodes. ii. Can be 2D or 3D iii. Edited in draw programs Commonly used for: i. Graphics that will be scaled (or resized) (a) Architectural drawings, CAD programs, flow charts (b) Logos needing to be displayed in various sizes without degrading quality ii. Cartoons and clip art iii. Internet websites iv. Fonts and specialized text effects

Lossless

no data is lost during compression.

Rotating

pivoting an object around its center point

Resolution

the amount of detail stored for an image. The higher the resolution, the higher the level of detail in the image. 1. PPI - pixels per inch a. The number of pixels in one inch b. More pixels per inch means better image quality but larger file size.

Transparency

the background of an image is "see-through" so that the graphic can blend into the background without having a white box around it.

Filters

used to apply special effects to an image