APPENDIX 3B Practical Considerations When Altering Digital Images

  1. Jerry Sedgewick

Published Online: 1 OCT 2008

DOI: 10.1002/9780470089941.eta03bs00

Current Protocols Essential Laboratory Techniques

Current Protocols Essential Laboratory Techniques

How to Cite

Sedgewick, J. 2008. Practical Considerations When Altering Digital Images. Current Protocols Essential Laboratory Techniques. 00:3B:A.3B.1–A.3B.30.

Author Information

  1. University of Minnesota, Minneapolis, Minnesota

Publication History

  1. Published Online: 1 OCT 2008
  2. Published Print: JAN 2008

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Worldwide, Adobe Photoshop is the primary means in research for altering images. Training on the use of this powerful tool most often is peer to peer within a laboratory, or it is self-taught through trial and error. As a result, varying amounts of visual data can be removed unwittingly; contrast- and brightness-enhancement of images can be done without adjusting color and grayscale levels to conform to the output (which includes publication, projection, web placement, and inclusion into Microsoft Word and Adobe Acrobat); images can be unethically altered; and pixelation can be introduced. Correct methods for use of Adobe Photoshop are outlined in this unit so that these errors can be avoided.


  • pixelation;
  • sampling resolution;
  • brightness;
  • contrast;
  • saturation;
  • pixels;
  • resampling;
  • gamma;
  • midtones