Raster Graphics 2.01 Investigate graphic image design. Raster Graphics

• Also called bitmap graphics • Consist of grids of tiny dots called pixels • Have a fixed resolution and cannot be resized without altering image quality • Edited in paint programs Notice the pixels Bitmap enlargement

Image source: http://graphicssoft.about.com/od/aboutgraphics/a/bitmapvector.htm Common Raster Formats

• GIF • JPEG • BMP • PNG • TIFF GIF – Graphics Interchange Format  Animation – Standard • Most common format for: format for animation on • Text the Internet. • Clip art, animations, icons,  Transparency – yes logos • Simple diagrams, line • Lossless compression drawings • Colors = 256 (8-bit) • Graphics with large blocks of a single color • Graphics with transparent areas Animated Gif • Images displayed on computer screens and on websites.

JPEG – Joint Photographic Experts Group

X Animation – No • Commonly Used For: X Transparency – No • Desktop publishing photographs • Lossy compression • Photographs and natural • Colors – 16.7 M (24-bit) artwork • High quality but larger file • Scanned photographs size than a GIF • Emailing photographs • Digital camera photographs BMP - Bitmap

X Animation – No • Commonly Used For: • Editing raster graphics X Transparency – No • Creating icons and • Uncompressed wallpaper • 256 colors • On-screen display • Large file size - not well suited for transfer across the Internet or for print publications

Icons PNG – Portable Network Graphics

X Animation – no • Commonly Used For:  Transparency – yes • Replacing GIF and TIFF images • Lossless compression • Online viewing of images • 256 colors • See examples at • Not suited for photographs http://graphicssoft.abo ut.com/od/freedownloa ds/l/blfreepng07.htm

TIFF – Tagged Image File Format X Animation – No • Commonly Used For: X Transparency – No • Storage container for faxes and other digital • Available in compressed images and un-compressed • To store raw bitmap data formats by some programs and • Compressed is advised devices such as scanners • Colors – 16 M (24-bit) • High resolution printing • Desktop Publishing images