Digital Color Imaging

This paper surveys current technology and research in the area of digital color imaging. In order to establish the background and lay down terminology, fundamental concepts of color perception and measurement are first presented us-ing vector-space notation and terminology. Present-day color recording and reproduction systems are reviewed along with the common mathematical models used for representing these devices. Algorithms for processing color images for display and communication are surveyed, and a forecast of research trends is attempted. An extensive bibliography is provided

The Study of paper surface efficiency

Paper surface efficiency (PSE) is a response resulting from the combination of paper gloss and oil absorptivity. A review of previous studies regarding the effect of paper surface efficiency on printed process color appearance is presented. This previous work related densitometric responses to PSE in terms of hue error and grayness. This current study investigated the PSE response in a similar manner, but densitometric responses were replaced by colorimetry. The colorimetric terms used were chroma (C*), huedifference (AH*), and lightness(L*). These correspond to hue error and grayness of the densitometric responses. Simple linear regression models relating the PSE and each response were constructed based on 13 kinds of paper printed with Hint cyan ink. The variable due to paper color was suppressed. The densitometric analysis generated results that verified Preucil\u27s investigation. These found that as the PSE increased, hue error and grayness decreased. The colorimetric analysis indicated a large color difference in the cyan ink due to PSE difference between coated and uncoated papers. This difference was more than 10 AE units. The difference was mainly due to the differences in chroma (AC*) and lightness (AL*); however, there was a small amount of hue-difference (AH*). The linear relationships between PSE vs. C* and PSE vs. L* were established and the correlation coefficient (r) was calculated. This analysis found that the correlations were significant and were used to predict the colorimetric responses (C*, L*) of an ink when printed on papers having different PSE. The models generated with the Flint Inks were tested with 9 additional papers printed at RIT with cyan ink to confirm the results and usefulness of the predictions. This analysis suggested the same concept as the previous one that there is a significant linear correlation between PSE vs. C* and PSE vs. L*- The straight lines that were generated were not the same for the two groups of prints that were investigated. This thesis contributes a useful framework for evaluating color using colorimetry as a function of PSE. With additional study, colorimetric analysis could become a better method for evaluating color in printing than densitometry

Lippman 2000: a spectral image database under construction

In support of research projects both within the Munsell Color Science Laboratory and outside which rely on having full knowledge of the spectral makeup of scenes, a number of methods for capturing spectral images are being explored. This project is named Lippmann2000 in honor of Gabriel Lippmann who in 1891 devised a method to perfectly reconstruct the spectral content of real world scenes. In spite of Lippmann’s invention, a more primitive three-channel model, first demonstrated by James Clerk Maxwell 30 years prior, has dominated the color imaging field. The Maxwellian model, universal in today’s silver halide and electronic color image capture systems, relies on the metameric properties of the human visual system to simulate the appearance of an original color. It has been recognized by those in the forefront of imaging research that the capture of full spectral data holds advantage over traditional three-channel methods. This paper describes our efforts to-date to build our database of spectral images

Multispectral photography for earth resources

A guide for producing accurate multispectral results for earth resource applications is presented along with theoretical and analytical concepts of color and multispectral photography. Topics discussed include: capabilities and limitations of color and color infrared films; image color measurements; methods of relating ground phenomena to film density and color measurement; sensitometry; considerations in the selection of multispectral cameras and components; and mission planning

An Experiment to Evaluate Skylab Earth Resources Sensors for Detection of the Gulf Stream

The author has identified the following significant results. An experiment to evaluate the Skylab earth resources package for observing ocean currents was performed in the Straits of Florida in January 1974. Data from the S190 photographic facility, S191 spectroradiometer and S192 multispectral scanner, were compared with surface observations. The anticyclonic edge of the Gulf Stream could be identified in the Skylab S190A and B photographs, but the cyclonic edge was obscured by clouds. The aircraft photographs were judged not useful for spectral analysis because vignetting caused the blue/green ratios to be dependent on the position in the photograph. The spectral measurement technique could not identify the anticyclonic front, but mass of Florida Bay water which was in the process of flowing into the Straits could be identified and classified. Monte Carlo simulations of the visible spectrum showed that the aerosol concentration could be estimated and a correction technique was devised

Earth Resources: A continuing bibliography (issue 32)

This bibliography list 580 reports, articles and other documents introduced into the NASA scientific and technical information system. Emphasis is placed on the use of remote sensing and geophysical instrumentation in spacecraft and aircraft to survey and inventory natural resources and urban areas. Subject matter is grouped according to agriculture and forestry, environmental changes and cultural resources, geodesy and cartography, geology and mineral resources, hydrology and water management, data processing and distribution systems, instrumentation and sensors, and economic analysis

Annotated Bibliography of Techniques for Image Enhancement and Interpretation in Remote Sensing

The purpose of this annotated bibliography is to provide the user of the Remote Sensing Information Subsystem (RSIS) with brief descriptions of recent research techniques of image enhancement and their applications to specific image interpretation problems. Table 2 of the May 1979 ASVT/RSIS Technical Report entitled "Functional Design Narrative Descriptions" listed digital image processing requirements of the RSIS. The references in this bibliography were chosen because they describe these processing requirements. The format of that table was modified slightly and used as the outline for Section One of this bibliography. The bibliography is not intended to be an exhaustive compilation of all pertinent articles. Such a collection would be outdated as soon as it was printed. It does, however, contain a broad sampling of the recent remote sensing literature. We tried not to include multiple references to the same technique, but some repetition was necessary in order to fully describe some procedures of image enhancement and interpretation.Bureau of Economic Geolog

Remote sensing in Michigan for land resource management: Highway impact assessment

An existing section of M-14 freeway constructed in 1964 and a potential extension from Ann Arbor to Plymouth, Michigan provided an opportunity for investigating the potential uses of remote sensing techniques in providing projective information needed for assessing the impact of highway construction. Remote sensing data included multispectral scanner imagery and aerial photography. Only minor effects on vegetation, soils, and land use were found to have occurred in the existing corridor. Adverse changes expected to take place in the corridor proposed for extension of the freeway can be minimized by proper design of drainage ditches and attention to good construction practices. Remote sensing can be used to collect and present many types of data useful for highway impact assessment on land use, vegetation categories and species, soil properties and hydrologic characteristics

Defect and thickness inspection system for cast thin films using machine vision and full-field transmission densitometry

Quick mass production of homogeneous thin film material is required in paper, plastic, fabric, and thin film industries. Due to the high feed rates and small thicknesses, machine vision and other nondestructive evaluation techniques are used to ensure consistent, defect-free material by continuously assessing post-production quality. One of the fastest growing inspection areas is for 0.5-500 micrometer thick thin films, which are used for semiconductor wafers, amorphous photovoltaics, optical films, plastics, and organic and inorganic membranes. As a demonstration application, a prototype roll-feed imaging system has been designed to inspect high-temperature polymer electrolyte membrane (PEM), used for fuel cells, after being die cast onto a moving transparent substrate. The inspection system continuously detects thin film defects and classifies them with a neural network into categories of holes, bubbles, thinning, and gels, with a 1.2% false alarm rate, 7.1% escape rate, and classification accuracy of 96.1%. In slot die casting processes, defect types are indicative of a misbalance in the mass flow rate and web speed; so, based on the classified defects, the inspection system informs the operator of corrective adjustments to these manufacturing parameters. Thickness uniformity is also critical to membrane functionality, so a real-time, full-field transmission densitometer has been created to measure the bi-directional thickness profile of the semi-transparent PEM between 25-400 micrometers. The local thickness of the 75 mm x 100 mm imaged area is determined by converting the optical density of the sample to thickness with the Beer-Lambert law. The PEM extinction coefficient is determined to be 1.4 D/mm and the average thickness error is found to be 4.7%. Finally, the defect inspection and thickness profilometry systems are compiled into a specially-designed graphical user interface for intuitive real-time operation and visualization.M.S.Committee Chair: Tequila Harris; Committee Member: Levent Degertekin; Committee Member: Wayne Dale

Retrieve: An Engineering Tool for Searching Remote Sensing and Environmental Engineering Databases

The design and development of a semi-automatic information retrieval system which features manual indexing, and an inverted file structure is presented. The system requires manual indexing done by an expert in the subject field to ensure high-precision searching. High-recall is achieved through the implementation of the inverted file. The system provides an interactive environment, a thesaurus for normalization of the indexing language, ranking of retrieved documents, and flexible output specifications. The purpose of this thesis is to present the design and development of in-house search-aid software for small document collections intended for Remote Sensing and Environmental Engineering users