Multi-media graphics--JOUR 205

Vectors vs. bitmaps

Multi-media graphics--JOUR 205

Vector images

• “Object-oriented” graphics

• Use points and curves to define shapes

• Objects remain independent and can be edited at any time.

• Can be scaled to any size without loss of detail

• File size usually smaller than bitmap files

Multi-media graphics--JOUR 205

Vector image, object selected

This point can beedited to change the shape of thecurve.

Multi-media graphics--JOUR 205

Vector image, curve edited

The point has been moved and adjacent line segments altered.

No other objects in the image are affected.

Multi-media graphics--JOUR 205

Vector image: 100%In print, these curves would be absolutely smooth. “Jaggies” are caused by the computer screen resolution.

Multi-media graphics--JOUR 205

Vector image: 1200%

Curves remain smooth because they are defined by math equations, not by pixels on a grid.

Multi-media graphics--JOUR 205

Bitmap images

• Composed of collections of bits or pixels

• Size-specific; appearance affected by color depth and output resolution

• Bitmaps don’t scale well.

• Edit only groups of pixels, not objects

• Realistic reproduction of photos, paintings

• File sizes can become very large.

Multi-media graphics--JOUR 205

Bitmap with rectangle selectionNote that an area of the image is selected, not a specific object.

Multi-media graphics--JOUR 205

Selection filled with color

Editing applies only to pixels within the selection, not to entire ‘objects.’

Multi-media graphics--JOUR 205

Bitmap image at 100%

Multi-media graphics--JOUR 205

Bitmap image at 800%Pixels that compose the image become very obvious as the image is enlarged.

Multi-media graphics--JOUR 205

Where bitmaps really shine

With bitmap images, you can achieve realistic effects that would be very difficult or impossible with vector images.