US 5,686,953 AGranted

Imaging system and method using linear perceived optical density interface

AssigneeMinnesota Mining and Manufacturing Company

InventorsTodd G. Langmade, Mark J. Giebler

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Abstract

An imaging system and method employ a linear perceived optical density interface that produces a substantially linear relationship between digital image values generated by an input imaging device and perceived optical densities of corresponding pixels within a visible representation of the image on film. The interface produces a linear change in perceived optical density in response to a linear change in the digital image values, enabling a system user to achieve predictable changes in appearance characteristics by simply adjusting the digital image values. The user can adjust the appearance characteristics in a flexible manner, without being constrained to a set of fixed transfer functions. The user can also perform desired formatting of the image at the input imaging device. The interface provides a single transfer function that is commonly applicable different input imaging devices, such that development of modality-specific transfer functions is unnecessary. The interface also eliminates the extensive hardware previously necessary for supporting a fixed set of transfer functions and formatting options, reducing cost and complexity.

Claims17

Dependent claims

A digital laser imaging system comprising:

an input imaging device for generating a plurality of digital image values representative of an image, each of said digital image values representing an optical density of said image at one of a plurality of pixels within said image;
a user input device, coupled to said input imaging device, for receiving input from a system user, said input including adjustments to said plurality of digital image values to modify one or more appearance characteristics associated with said image;
and
a laser imager, coupled to receive said plurality of digital image values, for forming, based on said plurality of digital image values, a visible representation of said image on photosensitive film, said laser imager including:
a scanning laser for exposing said film to form said visible representation of said image on said film, said scanning laser being operative in response to a plurality of laser drive values, wherein each of said plurality of laser drive values controls an exposure level of said scanning laser at one of a plurality of pixels within said visible representation of said image on said film,
a memory for storing a single conversion table, said conversion table mapping each of said digital image values to a corresponding one of said plurality of laser drive values according to a system transfer function such that a substantially linear relationship is produced between each of said digital image values and a perceived optical density of one of said pixels corresponding to the respective one of said digital image values within said visible representation of said image on said film, and
a processor for accessing said memory, converting said digital image values into said laser drive values based on said conversion table, and controlling the exposure level of said scanning laser based on said laser drive values to form said visible representation of said image on said film.

4 more elements

A digital laser imaging method comprising the steps of:

generating a plurality of digital image values representative of an image, each of said digital image values representing an optical density of said image at one of a plurality of pixels within said image;
receiving input from a system user, said input including adjustments to said plurality of digital image values to modify one or more appearance characteristics associated with said image;
and
forming, based on said plurality of digital image values, a visible representation of said image on photosensitive film, said step of forming said visible representation including the steps of:
scanning a laser to expose said film to form said visible representation of said image on said film, said laser being operative in response to a plurality of laser drive values, wherein each of said plurality of laser drive values controls an exposure level of said laser at one of a plurality of pixels within said visible representation of said image on said film,
accessing a memory storing a single conversion table, said conversion table mapping each of said digital image values to a corresponding one of said plurality of laser drive values according to a transfer function such that a substantially linear relationship is produced between each of said digital image values and a perceived optical density of one of said pixels corresponding to the respective one of said digital image values within said visible representation of said image on said film,
converting said digital image values into said laser drive values based on said single conversion table, and
controlling the exposure level of said scanning laser based on said laser drive values to form said visible representation of said image on said film.

5 more elements

Dependencies are inferred from the claim text.