Dynamic exposure control in color scanners

Giordano B. Beretta

doi:10.1117/12.271623

4 April 1997 Dynamic exposure control in color scanners

Giordano B. Beretta

Proceedings Volume 3018, Color Imaging: Device-Independent Color, Color Hard Copy, and Graphic Arts II; (1997) https://doi.org/10.1117/12.271623
Event: Electronic Imaging '97, 1997, San Jose, CA, United States

Abstract

The lightness values of white papers cover an approximate range of fifteen jnd. The tone range of scanners is adjusted for the lightest possible substrate. Therefore, a scan is usually preceded by a preview operation in which the image is subsampled and the data is analyzed to determine the actual tone range. In color facsimile and sheet-fed scanners that do not buffer the entire image, such an operation is not possible. We present a technique in which statistical methods are used to estimate the tone level of the paper. This estimate is used to set the parameters for a tone reproduction curve. The technique is incremental, the statistical data is gathered during the scan. While the scan progresses. The estimate is refined based on the increased amount of data available from the accumulated histogram. This has also the advantage that artifacts due to lamp warming during slow scans are automatically compensated.

Citation Download Citation

Giordano B. Beretta "Dynamic exposure control in color scanners", Proc. SPIE 3018, Color Imaging: Device-Independent Color, Color Hard Copy, and Graphic Arts II, (4 April 1997); https://doi.org/10.1117/12.271623

ACCESS THE FULL ARTICLE

INSTITUTIONAL
Select your institution to access the SPIE Digital Library.

SELECT YOUR INSTITUTION

PERSONAL
Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.

PERSONAL SIGN IN

No SPIE Account? Create one

PURCHASE THIS CONTENT

SUBSCRIBE TO DIGITAL LIBRARY

50 downloads per 1-year subscription

Members: $195

Non-members: $335 ADD TO CART

25 downloads per 1 - year subscription

Members: $145

Non-members: $250 ADD TO CART

PURCHASE SINGLE ARTICLE

Includes PDF, HTML & Video, when available