Understanding Image Histograms and Curves


Image Histograms

Color Channels

Histograms and Pixel Structure

Local Histograms

Using Histograms as a Scanner Tool

Prescan Histograms

Postscan Histograms

Evaluating Histogram Area

Image Exposure and Tone Curves

The Scanning Process

Changing Brightness and Contrast

Color Corrections



Interactive Demos

Setting Exposure

Setting Image Curves


The Photoshop Levels Function and Curves

Why Is There No Luminosity Tool?

Average Skin Tone

Using Histograms to Track Scanner Performance

Further Information

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Further Information

Adobe, 1998.  Print Publishing Guide. San Jose, California: Adobe Systems Incorporated.

Baxes, Gregory A. 1994. Digital Image Processing, Principles and Applications. New York, New York: John Wiley & Sons, Inc.

Burden, J.W. 1973. Graphic Reproduction Photography. New York, New York: Focal/Hastings House.

Burdick, Howard E. 1997. Digital Imaging. New York, New York: McGraw-Hill.

Larmore, Lewis 1965. Introduction to Photographic Principles. New York, New York: Dover Publications, Inc.

Sullivan, Michael J. 1998. Make Your Scanner a Great Design & Production Tool. Cincinnati, Ohio: North Light Books.

Harcourt, John. 1994. Scanning Essentials, The Nikon Guide to Desktop Film Scanning. Melville, New York: Nikon.

Revised: May 25, 2004 .