1,720,975 research outputs found
Perception of Mental States from Communication
No full textPerceiving means building or updating an internal model of the external world from the signals received by the sensors. In User-Modelling one of the problems is that of perceiving the user's beliefs and desires, i. e. building or updating a model of the user's mental state from his utterances. In this paper we present two speech acts based abductive methods to recognize the speaker's knowledge and intentions
A Prolog approach to image segmentation
No full textSegmentation is a main problem in computer vision. It attempts to supply primitives for higher-level processes of interpretation. A multithreshold approach has already given acceptable results. This paper presents a PROLOG implementation of a multithreshold system. The system uses the technique of recursive partition of two-dimensional images in quadrants to form maximal blocks; the data structure generated by this partition algorithm is known as a quadtree. The algorithms implemented concern image representation, connected regions, identification, and contour detection. The improvement of algorithms in a logic language rather than in a procedural one appeared to be of particular interest. The main reasons for this are implementation facility and the natural use of logic programming in the field of knowledge-based systems. In fact, a knowledge-based approach seems a reasonable solution to problems of assisted image understanding processes
Evolutionary image segmentation
No full textWe describe an approach to image segmentation based on a two-layer module that is executed until a good segmentation is achieved, providing an evolution of previous segmentation results at each execution. The first layer performs a global segmentation of an image of decreasing area at each evolution by adopting a genetic algorithm learning technique to select segmentation parameters that give better results. The second layer provides the input to the next evolution by selecting the segmented regions that need further optimisation. A main goal of our system is to perform the segmentation without using neither ground-truth information nor human judgement. Thus, edge detection is performed to assess the performance of region segmentation and to guide the evolution of segmentation. Experimental results are consistent with what is observed visually
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