Search results for " Segmentation"
showing 10 items of 462 documents
Differential diagnostic features of bone marrow biopsies in essential thrombocythemia
2004
Essential Thrombocythemia (ET) is a chronic myeloproliferative disorder (CMPD) characterized by a high platelet count and originating from a multipotent stem cell. For a long time, according to Polycythaemia Vera Study Group (PVSG) criteria, ET diagnosis has not included histopathological data. Bone Marrow (BM) histology was used only to exclude previous or other subtypes of Ph-CMD or Myelodysplastic syndromes (MDS). In addition, the lack of any cytogenetic or molecular-biological marker has made the discrimination between ET and cases of Reactive Thrombocytosys (RT) without a well known cause quite problematic. Analogously, the distinction of ET from the other Ph- CMPDs with similar clinic…
Improving color correction across camera and illumination changes by contextual sample selection
2012
International audience; In many tasks of machine vision applications, it is important that recorded colors remain constant, in the real world scene, even under changes of the illuminants and the cameras. Contrary to the human vision system, a machine vision system exhibits inadequate adaptability to the variation of lighting conditions. Automatic white bal- ance control available in commercial cameras is not sufficient to pro- vide reproducible color classification. We address this problem of color constancy on a large image database acquired with varying digi- tal cameras and lighting conditions. A device-independent color repre- sentation may be obtained by applying a chromatic adaptation…
Color and Flow Based Superpixels for 3D Geometry Respecting Meshing
2014
We present an adaptive weight based superpixel segmentation method for the goal of creating mesh representation that respects the 3D scene structure. We propose a new fusion framework which employs both dense optical flow and color images to compute the probability of boundaries. The main contribution of this work is that we introduce a new color and optical flow pixel-wise weighting model that takes into account the non-linear error distribution of the depth estimation from optical flow. Experiments show that our method is better than the other state-of-art methods in terms of smaller error in the final produced mesh.
Karhunen-Loe`ve transform applied to region-based segmentation of color aerial images
2001
The use of the Karhunen-Loeve transform (KLT) for region- based segmentation of aerial images by color and textural attributes is presented. Our aerial images are shown to be homogeneous color im- ages within the Karhunen-Loeve color representation space, which means they can be represented more easily and the region-based seg- mentation algorithms can be optimized. For texture analysis, the KLT is the basis of the local linear transform (LLT) and allows structural infor- mation about textures to be represented in an optimal and condensed manner. The LLT provides a system of textural analysis in the form of an adapted filter bank. We end the paper by presenting a method for merg- ing textur…
A neural network based automatic road signs recognizer
2003
Automatic road sign recognition systems are aimed at detection and recognition of one or more road signs from real-world color images. In this research, road signs are detected and extracted from real world scenes on the basis of their color and shape features. A dynamic region growing technique is adopted to enhance color segmentation results obtained in the HSV color space. The technique is based on a dynamic threshold that reduces the effect of hue instability in real scenes due to external brightness variation. Classification is then performed on extracted candidate regions using multilayer perceptron neural networks. The obtained results show good detection and recognition rates of the…
Colour segmentation based on a light reflection model to locate citrus fruits for robotic harvesting
1993
Abstract Colour segmentation with a vision system is a good procedure to identify and locate fruits in robotic harvesting. Natural illumination conditions present in these environments produce a very variable illumination of the scene, in addition, fruits are usually partially occluded, and complete visual information about them is not available. The colour segmentation used for these purposes must take into account the appearance of highlights and shadows that natural illumination conditions produce. A method based on the Dichromatic Reflection Model for the light reflected from the surface object is reported here. Through the assumption of this model the light rays reflected from points o…
Competition and product survival in the UK car market
2005
The paper examines the extent to which inter- and intra-firm competition influenced the survival of cars in the UK market between 1971 and 1998. It is shown that, while competition influenced product survival in all market segments within the UK car market, the nature of that competition differed between them. In the small family and large family car segments, intra-firm competition dominated inter-firm competition. In contrast, in the luxury/sports car segment only inter-firm competition conditions resulted in product survival. Evidence was also found that the luxury/sports car segment has grown more competitive over time and that firms marketing products in the family car segments have be…
SEGMENTACIÓN DEL COMPRADOR A DISTANCIA: UN ANÁLISIS DE LOS MEDIOS INTERNET Y TELEVISIÓN /
2005
La aparición de nuevos canales de venta como Internet y la Televisión está generando nuevas oportunidades de mercado para las empresas y está cambiando los hábitos de compra de los consumidores. No obstante, debido a la escasa experiencia de consumidores y empresas en este nuevo medio, la influencia del perfil del consumidor en la decisión de compra en los entornos virtuales es todavía desconocida. El objetivo del presente trabajo es analizar y comparar el perfil sociodemográfico y comportamental de los compradores que utilizan los medios Internet y Televisión, con el fin de identificar los segmentos prioritarios de consumidores para las empresas interesadas en la realización de una campaña…
Low-Rate Reduced Complexity Image Compression using Directionlets
2006
The standard separable two-dimensional (2-D) wavelet transform (WT) has recently achieved a great success in image processing because it provides a sparse representation of smooth images. However, it fails to capture efficiently one-dimensional (1-D) discontinuities, like edges and contours, that are anisotropic and characterized by geometrical regularity along different directions. In our previous work, we proposed a construction of critically sampled perfect reconstruction anisotropic transform with directional vanishing moments (DVM) imposed in the corresponding basis functions, called directionlets. Here, we show that the computational complexity of our transform is comparable to the co…
Segmenting the audience of a cause-related marketing viral campaign
2021
Abstract This paper analyses the attitudinal effect of a cause-related marketing campaign which becomes viral through social networks. This attitudinal response is observed in three Internet user segments with different affinity levels: i) strong (familiar with the sponsoring brand and the promoted cause); ii) intermediate (familiar with the brand or the cause); and iii) weak (without previous experiences of either the brand or the social cause). To develop our experiment, 360 Internet surfers agree to participate. Their attitudes were measured before and after the showing of a viral spot in which a pet food brand encourages pet adoption. Our results show that a viral campaign works perfect…