Optimization for Hue Constant RGB Sensors

We present an optimization technique to find hue constant RGB sensors. The hue representation is based on a log RGB opponent color space that is invariant to brightness and gamma. While modeling the visual response did not derive the opponent space, the hue definition is similar to the ones found in CIE Lab and IPT. Finding hue constant RGB sensors through this optimization might be applicable in color engineering applications such as finding RGB sensors for color image encodings

MilkGuard: Predictive Modeling and Mobile App Development for Affordable, Usable Breast Milk Diagnostic

Breast milk is considered the gold standard of infant nutrition, but some infants around the world lack access to it due to maternal health complications or other considerations. Human breast milk banks do exist to try to alleviate this problem, but most are underfunded and have high operational costs, making it difficult for some infants to obtain safe, reliable donated breast milk. Existing methods of testing breast milk are expensive, so the MilkGuard project was conceptualized in 2017 as a fast, economical, and highly usable bacterial contamination detection system. Prior to this year, previous MilkGuard teams had developed a system that was faster and more affordable than prior methods, but its main drawbacks were that it was difficult to use and that it lacked the sensitivity to detect low Escherichia coli (E. coli) contamination levels. To ameliorate these drawbacks, our goals for this year were 1) to improve MilkGuard’s sensitivity to the Human Milk Banking Association of North America’s (HMBANA) lower limit of detection standard of 104 CFU/mL, 2) to increase the ease of the assay process, and 3) to achieve these objectives in an economical and environmentally-friendly way. Through COMSOL Multiphysics software simulations, we proved the possibility of realistically optimizing biosensor parameters on a computer. Since the simulations were virtual, we discovered an optimal biosensor configuration without the need to purchase, manufacture, and test hundreds of physical sensors. Future teams can quickly confirm these results by building a physical sensor in the lab. We also developed the MilkGuard app, which greatly simplifies the colorimetric analysis process for the user. This mobile app uses our improved color-analysis algorithm which improves detection sensitivity around the HMBANA’s lowered limit of detection standard, given the same image data to analyze. The efficacy of our new color analysis algorithm can be confirmed by future teams in the lab, and our current regression curve can be made more robust with a larger sample size. Taken together, our developments this year have increased the usability and sensitivity of the MilkGuard system, which can improve bacterial contamination testing by milk banks and move one step closer to equitable access to safe breast milk for infants around the world

DigitalBeing: an Ambient Intelligent Dance Space.

DigitalBeing is an ambient intelligent system that aims to use stage lighting and lighting in projected imagery within a dance performance to portray dancer’s arousal state. The dance space will be augmented with pressure sensors to track dancers’ movements; dancers will also wear physiological sensors. Sensor data will be passed to a three layered architecture. Layer 1 is composed of a system that analyzes sensor data. Layer 2 is composed of two intelligent lighting systems that use the analyzed sensor information to adapt onstage and virtual lighting to show dancer’s arousal level. Layer 3 translates lighting changes to appropriate lighting board commands as well as rendering commands to render the projected imagery

Toward color image segmentation in analog VLSI: Algorithm and hardware

Standard techniques for segmenting color images are based on finding normalized RGB discontinuities, color histogramming, or clustering techniques in RGB or CIE color spaces. The use of the psychophysical variable hue in HSI space has not been popular due to its numerical instability at low saturations. In this article, we propose the use of a simplified hue description suitable for implementation in analog VLSI. We demonstrate that if theintegrated white condition holds, hue is invariant to certain types of highlights, shading, and shadows. This is due to theadditive/shift invariance property, a property that other color variables lack. The more restrictive uniformly varying lighting model associated with themultiplicative/scale invariance property shared by both hue and normalized RGB allows invariance to transparencies, and to simple models of shading and shadows. Using binary hue discontinuities in conjunction with first-order type of surface interpolation, we demonstrate these invariant properties and compare them against the performance of RGB, normalized RGB, and CIE color spaces. We argue that working in HSI space offers an effective method for segmenting scenes in the presence of confounding cues due to shading, transparency, highlights, and shadows. Based on this work, we designed and fabricated for the first time an analog CMOS VLSI circuit with on-board phototransistor input that computes normalized color and hue

Ensemble of Different Approaches for a Reliable Person Re-identification System

An ensemble of approaches for reliable person re-identification is proposed in this paper. The proposed ensemble is built combining widely used person re-identification systems using different color spaces and some variants of state-of-the-art approaches that are proposed in this paper. Different descriptors are tested, and both texture and color features are extracted from the images; then the different descriptors are compared using different distance measures (e.g., the Euclidean distance, angle, and the Jeffrey distance). To improve performance, a method based on skeleton detection, extracted from the depth map, is also applied when the depth map is available. The proposed ensemble is validated on three widely used datasets (CAVIAR4REID, IAS, and VIPeR), keeping the same parameter set of each approach constant across all tests to avoid overfitting and to demonstrate that the proposed system can be considered a general-purpose person re-identification system. Our experimental results show that the proposed system offers significant improvements over baseline approaches. The source code used for the approaches tested in this paper will be available at https://www.dei.unipd.it/node/2357 and http://robotics.dei.unipd.it/reid/

Class Separation Improvements in Pixel Classification Using Colour Injection

This paper presents an improvement in the colour image segmentation in the Hue Saturation (HS) sub-space. The authors propose to inject (add) a colour vector in the Red Green Blue (RGB) space to increase the class separation in the HS plane. The goal of the work is the development of an algorithm to obtain the optimal colour vector for injection that maximizes the separation between the classes in the HS plane. The chromatic Chrominace-1 Chrominance-2 sub-space (of the Luminance Chrominace-1 Chrominance-2 (YC1C2) space) is used to obtain the optimal vector to add. The proposal is applied on each frame of a colour image sequence in real-time. It has been tested in applications with reduced contrast between the colours of the background and the object, and particularly when the size of the object is very small in comparison with the size of the captured scene. Numerous tests have confirmed that this proposal improves the segmentation process, considerably reducing the effects of the variation of the light intensity of the scene. Several tests have been made in skin segmentation in applications for sign language recognition via computer vision, where an accurate segmentation of hands and face is required

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