Graphic File Formats

1
Lesson 3
Graphic File Formats
Ray W. Moore ramoore_at_vt.edu October 26, 2001
2
BMP Windows Bitmap

• Not compressed or limited compression
• Lossless
• The graphic was successfully inserted into
  PowerPoint.
• Internet Explorer used QuickTime Viewer as a
  stand-alone viewer.

3
EPS Encapsulated PostScript

• Not compressed
• Lossless or lossy designation not applicable
• The graphic was successfully inserted into
  PowerPoint.
• Internet Explorer used Microsoft Picture It! as a
  stand-alone viewer.

4
GIF Graphics Interchange Format

• Highly Compressed
• Lossless
• The graphic was successfully inserted into
  PowerPoint.
• Internet Explorer used QuickTime Player as
  stand-alone viewer.

5
JPG Joint Photographic Experts Group

• Compressed 51 201
• Lossy
• The graphic was successfully inserted into
  PowerPoint.
• Internet Explorer was able to view the image with
  no stand-alone viewer.

6
PCT Macintosh Picture

• Limited compression
• Lossless
• The graphic was successfully inserted into
  PowerPoint.
• Internet Explorer used Microsoft Picture It! as a
  stand-alone viewer.

7
PCX PC Paintbrush

• RLE Compression Method
• Lossless
• The graphic could not be inserted into
  PowerPoint.
• Internet Explorer used QuickTime Player as a
  stand-alone viewer.

8
PDF Portable Document Format

• Limited Compression
• Lossless
• The graphic could not be inserted into
  PowerPoint.
• Internet Explorer used Acrobat Reader as a
  stand-alone viewer.

9
PNG Portable Network Graphics

• Highly Compressed
• Lossless
• The graphic was successfully inserted into
  PowerPoint.
• Internet Explorer used QuickTime Viewer as a
  stand-alone viewer.

10
PSD Photoshop Document

• Not Compressed
• Lossless
• The graphic could not be inserted into
  PowerPoint.
• Internet Explorer used QuickTime Viewer as a
  stand-alone viewer.

11
TGA Truevision Targa

• Either compressed or not compressed
• Lossless
• The graphic was successfully inserted into
  PowerPoint.
• Internet Explorer used QuickTime Viewer as a
  stand-alone viewer.

12
TIF Tagged Image File Format

• Compression varies
• Lossless
• The graphic was successfully inserted into
  PowerPoint.
• Internet Explorer used QuickTime Viewer as a
  stand-alone viewer.

13
WMF Windows Metafile

• No compression
• Lossless or lossy designation not applicable
• The graphic was successfully inserted into
  PowerPoint.
• Internet Explorer used QuickTime Viewer as a
  stand-alone viewer.

14
Which graphic file format to use?

• Despite hours of searching the internet, I still
  have more questions than answers concerning
  graphic file formats. However, there seem to be
  a few general principles to consider
• File size is extremely important. The best
  choice with that consideration in mind is JPEG.
  The problem is that JPEG uses a lossy compression
  method which can result in image deterioration,
  especially when sharp edges exist. JPEG is
  well-suited for photographs and other real
  images.
• GIF (89a) supports transparency and JPEG does
  not.
• GIF should only be used for simple images with
  relatively few colors.
• While PNG may replace GIF, too few browsers
  support it yet.
• Most other formats are specific to only one
  platform or to their own programs.
• It is important to save work in progress in a
  lossless format. Therefore, works in progress
  should be saved in their original format. One
  good idea is to save a version in a lossless
  format even when choosing a lossy format for
  transmission or presentation.
• My conclusion is to use GIF and JPEG primarily
  for presentation and the original format for
  works-in-progress.