Digital Imaging
Provides a comprehensive practical guide to the entire digital chain, from capture -- with coverage of digital cameras, to output -- with extensive information on image adjustments and colour management.
TABLE OF CONTENTS Digital Imaging
Chapter 4: Scanning and Image Adjustment
Aims
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To offer an independent resource of technical information.
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To develop an understanding of procedures involved in scanning photographic images.
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To develop knowledge and understanding about the control that can be exercised over digital image structure.
Objectives
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Capture digital image files using knowledge concerning:
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resolution
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image mode
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file format and output size
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image correction and control
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Introduction
It is essential that the information captured during the scanning process is as faithful to the original detail as possible. The complete tonal range of the original (from the deep shadow detail to the bright highlight detail) should be captured. The colour should be recorded accurately (a colour cast should not be apparent). Missing information cannot be replaced later (magic wand or no magic wand).
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To maximise the quality of the final digital image use a high quality original and spend some time getting the best possible scan from the print or film.
Preparing to scan
A good scan will:
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Have sufficient pixels for the required image size and output device (see 'Digital basics > Calculating image resolution for output ', page 13).
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Capture the full range of highlight and shadow detail of the original (see 'Adjusting tonality and colour ', page 51).
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Be colour corrected to that of the original (see 'Removing a colour cast ', page 57).
To ensure a good scan you must have:
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Knowledge of the file size and/or scanning resolution (see 'Scanning resolution ', page 50).
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A clean original image and scanning device.
Copyright Mark Galer and Les Horvat 2001 under license agreement with Books24x7
