Thesis (M.S.)--Rochester Institute of Technology, 1987. / Typescript. Includes bibliographical references (leaves 83-86).

Thesis (M.F.A.)--Rochester Institute of Technology, 1990. / Typescript.

Thesis (Ph. D.)--Michigan State University. Media and Information Studies, 2008. / Title from PDF t.p. (viewed on July 23, 2009) Includes bibliographical references (p. 218-234). Also issued in print.

No description available.

Colour images can be formed by the combination of stimuli in three primary colours. As a result, digital colour images are typically represented as a triplet of values, each value corresponding to the stimulus of a primary colour. The precise stimulus that the eye receives as a result of any particular triplet of values depends on the display device or medium used. Photographic film is one such medium for the display of colour images. This work implements a software system to calibrate the response given to a triplet of values by an arbitrary combination of film recorder and film, in terms of a measurable film property. The implemented system determines the inverse of the film process numerically. It is applied to calibrate the Optronics C-4500 colour film writer of the UBC Laboratory for Computational Vision. Experimental results are described and compared in order to estimate the expected accuracy that can be obtained with this device using commercially available film processing. / Science, Faculty of / Computer Science, Department of / Graduate

The objectives of this research were (1) to develop scales of preferred image sharpness for thermal dye transfer prints and (2) to relate these scales to an objective measurement of image quality. Interval scales were developed using two different indirect scaling techniques, paired comparison and rank ordering, for three groups of participants (novice photographers, advanced amateur photographers, and Kodak image quality experts). Differences between scales developed through the separate scaling procedures were minor, suggesting that either procedure would produce a reliable and valid interval scale. Given the time required to perform the method of paired comparisons, the method of rank ordering would likely be the preferred procedure. The results from multiple range tests of the interval scales found that higher levels of image sharpening (filter levels 1.5x to 2.5x) were generally preferred. However, for some conditions, particularly the portrait, lower levels of sharpening were generally preferred. While it appears that the preferred level of image sharpness may be somewhat dependent upon scene content, participants always preferred a small amount of sharpening to none at all. For all conditions examined, stimuli that received no sharpening were the least preferred. In relating interval scales to an objective measure of image quality, scale values developed from within a level of addressability were highly correlated with values of modified MTFA for all participant groups. These correlations show that a strong relationship exists between preferred levels of image sharpness and increasing levels of luminance modulation for edges in thermal prints. However, values of modified MTFA were not well correlated with interval scale values developed from experts participants for the between levels of addressability portion of the experiment. Values of MTFA were considered modified due to limits that were imposed on the bounds of integration. These results suggest that the preferences of experts may not represent those of the average consumer for desired levels of thermal print sharpness. / Ph. D.

Thesis (B.S.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 1982. / MICROFICHE COPY AVAILABLE IN ARCHIVES AND ENGINEERING / Includes bibliographical references. / by David P. Harrahy. / B.S.

This project explores the technological hybridity of early color formats against medium-specific definitions of photography and cinema. It argues for the centrality of female photographers as early practitioners and innovators of color photography in the United States and England. It claims that color featured prominently in the late Victorian and Edwardian imperial imaginary to construct orientalizing views of colonial subjects. Early color photographic technologies (1890-1920) are situated within contemporaneous scientific and social debates around color. These debates evince a crucial epistemological shift in the conceptualization of color: from a relational phenomenon of the human senses and world to an empirical and physical one affixed to objects. The first chapter advances the color image as an event: a co-production of the human sensorium and machine technologies, rendered in time and space. The second chapter charts the intersections of photography, color, and gender discourses, with an emphasis on three female photographers who successfully marshalled the gendered biases of color in order to establish expressive modes and photographic careers in the new color medium. The gendering of color also helped to define orientalist photography and film of the British colonial era, particularly that of India, the subject of the third chapter. Comparing color in orientalist depictions of India and the use of color in Indian photographic portraits compels us to reconsider the links between technology and subjectivity as well as modernity and colonialism. This dissertation seeks not only to rewrite the history of early color photography but also to reconfigure understandings of aesthetic modernity as a complex imbrication of art, technology, gender, and imperialism.

The quality of a digital image pipeline relies greatly on its color reproduction which should at a minimum handle the color constancy, and the final judgment of the excellence of the pipeline is made through subjective observations by humans. This dissertation addresses a few topics surrounding the color processing of digital image pipelines from a practical point of view. Color processing fundamentals will be discussed in the beginning to form a background understanding for the topics that follow.A memory color assisted illuminant estimation algorithm is then introduced after a review of memory colors and some modeling techniques. Spectral sensitivity of the camera is required by many color constancy algorithms but such data is often not readily available. To tackle this problem, an alternative method to the spectral characterization for color constancy parameter calibration is proposed. Hue control in color reproduction can be of great importance especially when memory colors are concerned. A hue constrained matrix optimization algorithm is introduced to address this issue, followed by a psychophysical study to systematically arrive at a recommendation for the optimized preferred color reproduction. At the end, a color constancy algorithm for high dynamic range scenes observing multiple illuminants is proposed. / Graduation date: 2012

To reduce cost, many digital cameras use a single sensor array instead of using three arrays for the red, green and blue. Thus at each pixel location only the red, green or blue intensity value is available. And to generate a complete color image, the camera must estimate the missing two values at each pixel location .Color filter arrays are used to capture only one portion of the spectrum (Red, Green or Blue) at each location. Various arrangements of the Color Filter Array (CFA) are possible, but the Bayer array is the most commonly used arrangement and we will deal exclusively with the Bayer array in this thesis. Since each of the three colors channels are effectively downsampled, it leads to aliasing artifacts. This thesis will analyze the effects of aliasing in the frequency- domain and present a method to reduce the deterioration in image quality due to aliasing artifacts. Two reference algorithms, AH-POCS (Adams and Hamilton - Projection Onto Convex Sets) and Adaptive Homogeneity-Directed interpolation, are discussed in de- tail. Both algorithms use the assumption that there is high correlation in the high- frequency regions to reduce aliasing. AH-POCS uses alias cancellation technique to reduce aliasing in the red and blue images, while the Adaptive Homogeneity-Directed interpolation algorithm is an edge-directed algorithm. We present here an algorithm that combines these two techniques and provides a better result on average when compared to the reference algorithms.