Search results for "Color space"
showing 6 items of 36 documents
ROBUST ROAD SIGNS SEGMENTATION IN COLOR IMAGES
2012
International audience; This paper presents an efficient method for road signs segmentation in color images. Color segmentation of road signs is a difficult task due to variations in the image acquisition conditions. Therefore, a color constancy algorithm is usually applied prior to segmentation, which increases the computation time. The proposed method is based on a log-chromaticity color space which shows good invariance properties to changing illumination. Thus, the method is simple and fast since it does not require color constancy algorithms. Experiments with a large dataset and comparison with other approaches, show the robustness and accuracy of the method in detecting road signs in …
Simultaneous Color Contrast in Goldfish— a Quantitative Study
1997
AbstractA set of 9–15 colored test fields was presented to goldfish. In Experiment 1, test field hues ranged from green through yellow to red; in Experiment 2, the hues varied from blue through gray to yellow. In the training conditions, the test fields were presented with a gray or black surround. The fish learned to choose one intermediate test field hue by rewarding them with food. In the test conditions, the color of the surround was changed from gray to green, or red (Experiment 1), and from black to blue, or yellow (Experiment 2). The choice behavior of the goldfish changed substantially: one of the test fields other than the training test field was preferred. Direction and strength o…
Intelligent eye
2010
This paper describes Intelligent Eye, a mobile phone interactive leisure guide that offers location-based multimedia information. The information offered is related to the user's position, so the main goal of this work is the development of an efficient system to detect where the user is pointing his/her camera at by means of a content-based image retrieval algorithm (CBIR). The CBIR procedure uses color histograms in the HS color space extracted from images, and employs Kullback-Leibler divergence as the similarity measure. Intelligent Eye can be used in a wide range of camera-equipped mobile phones; however, efficiency is improved if GPS data is available. In order to outperform other sys…
Contrast sensitivity perimetry tests along the cardinal directions in color space: Correlation with the properties of the neural mechanisms mediating…
2014
It is well-known the advantages of measuring chromatic and achromatic contrast sensitivity for detecting pathologies. But these measurements are rarely used in clinical practice, due the complexity of the measurements and the examinator specialization. In fact, there is not a complete characterization of the response of the visual pathways to achromatic and chromatic spatio-temporal frequency stimuli. We have designed a new experimental device that facilitates these measurements and allow us to characterize the visual response in healthy patients. In this paper, we evaluated the responses of the visual pathways in healthy patients.
Automatic Conjunctival Provocation Test Using Hough Transform of Extended Canny Edge Maps
2013
Computer-aided diagnosis is developed for assessment of allergic rhinitis/rhinoconjunctivitis measuring the relative redness of sclera under application of allergen solution. The patient’s eye images are taken from commercial digital camera. The iris is robustly localized using a gradient-based Hough circle transform. From the center of the pupil, the region of interest within the sclera is extracted using geometric anatomybased a-priori information. The red color pixels are extracted thresholding in the hue, saturation and value color space. Then, redness is measured by taking mean of saturation projected into zero hue. Evaluation is performed with 92 images taken from 13 subjects, 8 respo…
Spatiocolorimetric neighborhood hypergraph and Image Processing Applications : Noise Removal and Edge Detection.
2004
In this document, we are interested in image modeling by the means of the hypergraph theory. Our contribution is essentially centered on the determination of the properties resulting from this theory and on the analysis from their adequacy with image problems, particularly edge and noise detection.First, we study the image spatiocolorimetric neighborhood hypergraph representation. Three representations are respectively presented incorporating global properties, local properties and similarity functions. Then, we use the hypergraph properties generated by the representation in order to define the structural models of noise and edge. This enables us to deduce the algorithms of noise suppressi…