Multilevel data fusion for the detection of targets using multispectral image sequences

An approach is presented to the long range automatic detection of vehicles, using multisensor image sequences, The method is tested on a database of multispectral image sequences, acquired under diverse operational conditions, The approach consists of two parts, The first part uses a semisupervised approach, based on texture parameters, for detecting stationary targets, Far each type of sensor one learning image is chosen, Texture parameters are calculated at each pixel of the !earning images and are combined using logistic regression into a value that represents the conditional probability that the pixel belongs to a target given the texture parameters, The actual detection algorithm applies the same combination to the texture features calculated on the remainder of the database (test images), When the results of this feature-level fusion are stored as an image, the local maxima correspond to likely target positions, These feature-level-fused images are calculated for each sensor. In a sensor fusion step, the results obtained per sensor are then combined again, Region growing around the local maxima is then used to detect the targets, The second part of the algorithm searches for moving targets, To detect moving vehicles, any motion of the sensor must be detected first, if sensor motion is detected, it is estimated using a Markov random field model, Available prior knowledge about the sensor motion is used to simplify the motion estimation. The estimate is used to warp past images onto the current image in a temporal fusion approach and moving targets are detected by thresholding the difference between the original and warped images. Decision level fusion combines the results from both parts of the algorithm, (C) 1998 Society of Photo-Optical Instrumentation Engineers.