1. Sci Vis I Exam Review
Unit 6
File Formats

2. File Formats Native vs. Non-Native
Each software package has a NATIVE file format or format assigned by DEFAULT.
NON-NATIVE file formats result from using Open or Save As and using a file format other than the software’s NATIVE file format.

3. Familiar Native File Formats
Microsoft
Word .doc
Excel .xls
Powerpoint .ppt
3D Studio Max .3ds
Photoshop .psd

4. Two Types of File Compression
COMPRESSED files have been altered to produce smaller files sizes (uses less memory)
Two Types of File Compression
Lossy: removes bits of color information so image quality is permanently lost
Lossless: reduces to image that looks exactly the same.
LZW is a lossless compression algorithm (program that compresses files).

5. Image File Formats TIFF (Tagged Image File Format)
for cross-platform files. Example: files that need to be used on Windows and Mac
High-quality used for professional printing
Bitmap files
Compressed using Lossless LZW

6. Image File Formats JPEG (Joint Photographic Experts Group)
Algorithm for static images (not a file format)
Used for photographs, art, complex images
Lossy compression
Wide range of ratios between file size & image quality - the more compression the lower the image quality
Ok for electronic purposes but not for print

7. Image File Formats GIF (Graphical Interchange Format)
Compressed images
Used on any computer
Lossless compression using LZW (3:1 – 5:1 compression)
Better for less complex images such as cartoons, simple clip art, text not printing (only 72PPI)
Can be animated
Can have transparancy

8. Image File Formats BMP (Bitmap) Used on Windows computers
Used for screen backgrounds

9. Image File Formats AVI (Audio Video Interleaved)
Developed by Microsoft
Played with Windows Media Player
Store audio & video data