1. Graphic File Formats

2. Objectives Understand the difference between two major categories of computer graphic images Investigate the differences between various file formats Generalize formats to the type of software that creates them Establish a philosophy of use for various graphic file formats

3. Native File Format

4. Two Categories of Formats Bitmapped Vector

5. Bitmapped Formats Images are created by individual pixels displayed in various colors.

6. Bitmapped Formats Remember, each pixel can hold up to 24 bits (3 bytes) of color information

7. Bitmapped Formats Bitmapped formats have a fixed resolution Can NOT be resized without some effects on the clarity of the image

8. Bitmapped Formats Bitmapped formats are best suited for “photographic” quality images

9. Bitmapped Formats Scanners and digital cameras acquire images in bitmapped formats

10. Common Bitmapped File Formats TIF JPG BMP PIC GIF PNG PSD PCX

11. TIF Format T agged I mage F ile format. Standard between MAC and PC bitmap graphics. Handles multiple channel files. i.e. RGB i.e. Alpha Channels

12. TIF Format Writes a "header" that tells software what information is contained. Header may increase file size. –Not really a problem with modern hardware

13. TIF Format Uses a LZW compression scheme. No data lost, just compressed.

14. JPG (Jpeg) Format J oint P hotographic E xperts Group A file format and compression scheme. Emerging as a standard format for photos. Internet use.

15. JPG (Jpeg) Format “Lossy” compression- Reduces data during save. Data loss can be controlled. Can reduce file size in a ratio between 10:1 and 20:1.

16. BMP Format Microsoft native file format PC system compatible –DOS –Windows –OS/2 No MAC compatibility.

17. BMP Format Photoshop encodes to 1, 4, 8, 24 bit color but.bmp can not support channels. No file space savings for photos with.bmp. - Try a JPG!

18. PIC (Pict) Format A MAC native file format. Not PC operating system compatible. Can do 24 bit color plus an extra 8 bits. Any MAC monitor can display 32 bit PICT files

19. PICT Format MAC system format used to exchange data via clipboard.

20. GIF Format Graphics Interchange Format. Created by Compuserve to speed downloading of graphics. Limited to 256 colors. Compression format

21. GIF Format Can be both interlaced and non-interlaced Common Internet file format –87 –89a (interlaced, with one transparent color)

22. PNG Format P ortable N etwork G raphics New format targeted for Internet use Can support up to 48 bit color Big compression factor Can support multiple transparent colors

23. PSD Format Photoshop native file format. Supports all image types from line art to photos. Increasing compatibility with other software.

24. PSD Format PSD can hold an infinite amount of channels! Each layer can hold 24 channels. Infinite amount of layers are possible. Subject to available RAM!!!!

25. Multi-Channel to.GIF

26. PCX Format From ZSoft Corp. Many versions exist. Great for indexed, grayscale and line art. Supports only one channel.

27. PCX Format Photoshop only supports PCX version 5! Convert.pcx to RGB to use most Photoshop tools. PC Paintbrush format.

28. Kodak Photo CD - PCD Kodak format for images stored on Kodak Photo CD. Uses YCC color model. Limited to five image sizes.

29. Kodak Photo CD - PCD Photoshop opens as a LAB color model. Photoshop can not save as a PhotoCD format.

30. Bitmapped Formats And Pixels

31. Vector Formats Images are a series of pixels that are "turned on" based on a mathematical formula.

32. Vector Formats Vector Formats are basically defined by shapes and lines No more than 256 colors Clip Art

33. Vector Formats Not resolution dependent Infinitely scalable Not appropriate for photo realistic images

34. Common Vector File Formats WMF AI Post Script CGM Fonts DRW CIL

35. WMF Format W indows M etafile F ormat. Designed for easy exchange between Windows programs via clipboard. Common clipart format.

36. PostScript Format Developed by Adobe Systems for typefaces. Expanded for many graphic elements. Encapsulated Post Script (.eps) is of this format.

37. PDF Format Adobe Acrobat file format. Portable Document Format

38. PDF Format Integrates color, graphics and text Searchable format

39. CGM Format C omputer G raphics M etafile Most common DOS- based format Used by - –Harvard Graphics –Freelance Graphics –Others

40. CGM Format Older versions of format may not load cleanly into modern versions of software Can support very elaborate graphics A "schizophrenic" file format!

41. Vector Formats And Shapes

42. Software Choices Traditionally, different software creates either bitmapped or vector art This is changing!

43. Software Choices For bitmapped, names that include the words “Paint” or “Photo” indicates that the primary function of the software is to create and manipulate bitmapped formats

44. Software Choices For bitmapped, names that include the words “Paint” or “Photo” indicates that the primary function of the software is to create and manipulate bitmapped formats Examples – –Adobe Photoshop –Deluxe Paint –Photoshop Elements –Macromedia Fireworks –Corel Photo-Paint –Paint Shop Pro

45. Software Choices For vector art, names that include the words “Draw” or “Illustrator” indicates that the primary function of the software is to create and manipulate bitmapped formats

46. Software Choices For vector art, names that include the words “Draw” or “Illustrator” indicates that the primary function of the software is to create and manipulate bitmapped formats Examples – –Adobe Illustrator –Corel DRAW –Microsoft Draw –Macromedia Freehand –Serif DrawPlus –Macromedia Flash

47. Software Choices Most modern versions of bitmapped software also include draw tools Photoshop 6.0 now can create vector art.

48. Software Choices Adobe Acrobat, desktop publishing, etc. software is friendly to both categories of graphic types

49. When to Use What and When!?!? What are the requirements of your output device?

50. When to Use What and When!?!? Image QualityFile Size

51. When to Use What and When!?!? Image QualityFile Size Photo Image Illustration

52. When to Use What and When!?!? Image QualityFile Size Photo Image Illustration Internet Other Computer Devices

53. Curriculum Content and Activities created by Dr. Mark Mortensen Dept. of Technology & Cognition University of North Texas