The increasing capacity of modern computers has created the opportunity to routinely process the very large data sets derived by digitizing aerial photographs. The very fine resolution of such data sets makes them better suited than satellite imagery for some applications; however, there may be problems in implementation resulting from variation in radial distortion and illumination across an aerial photograph. We investigated the feasibility of using local operators (e.g., non-overlapping moving window means and standard deviations) as auxiliary data for generating stand development classes via three steps: (i) derive 6 local operators intended to represent texture for a 16 by 16 m window corresponding to a forest inventory sampling unit, (ii) apply a calibration process (e.g., accounting for location relative to a photo's principal point and solar position) to these local operators, and (iii) apply the calibrated local operators to classify the forest for stand development. Results indicate that calibrated local operators significantly improve the classification compared to what is possible using uncalibrated local operators and satellite images.
We explore the potential of variance matrices to represent not just statistical error on object pose estimates but also partially constrained degrees of freedom. Using an iterated extended Kalman filter as an estimation tool, we generate, combine and predict partially constrained pose estimates from 3D range data. We find that partial constraints on the translation component of pose which occur frequently in practice are handled well by the method. However, coupled partial constraints between rotation and translation are, in general, non-linear and cannot be represented by this method.
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