This paper proposes a method based on hidden Markov models to detect flames in video.In addition to motion and color analysis,flame flicker process is detected by using a hidden Markov model.Results show that Markov models representing the flame and flame colored ordinary moving object are effective to distinguish flame flicker from motion of flame colored moving object.False alarms are reduced when using this method,it may have a practical application.
This paper proposes a method about image correspondence based on a speed robust feature descriptor.This relies on integral images and Fast-Hessian detector to extract interest points.For each feature point,the dominant orientation is assigned by computing Haar-wavelet responses.Based on these orientations constructing a window around the feature point,the feature points are decrypted by the sum of Haar-wavelet responses on the domination orientation and the verticality.Image correspondences are made based on distance between these descriptors.
Neural networks is used to estimate three-dimensional(3D) rigid motion parameters based two constraints.The one is based on 3D correspondences.The points' coordinates before motion are updated by the presupposed motion parameters and then compared to those after motion.The other is based two-dimensional(2D) motion fields.The motion fields from presupposition are compared to those computed from image sequences.Both network updates its weights by newton-raphson procedure for minimizing the error measures.Experimental results are presented for validating the proposed scheme.
A method on detection of feature points based on muti-scale space is presented.At fist Gaussian pyramid and DOG pyramid is built,the extreme value is detected,then keypoints with low contrast keypoints is rejected,at last an orientation and the gradient magnitude are assigned.The features using this method are invariant to image rotation,change in illumination,scale,and are shown to provide robust affine distortion,change in viewpoint,and addition of noise.The parameters is given and the results is analyzed.
