Ricardo Galego

Learn More
This paper departs from traditional calibration in the sense that the pixels forming the camera have a completely unknown topology. Previous works have shown that the statistical properties of natural scenes, and a uniform motion of a camera both in translation and rotation, allow determining the topology of a central camera [10, 6]. Here we show that there(More)
Drip-irrigated BuÂlida apricot trees (Prunus armeniaca L.) on Real Fino apricot rootstock were submitted, for 4 consecutive years, to water stress by withholding irrigation at different phenological periods: during the period of ̄owering-fruit set which lasted around 1 month (T-1 treatment); during stages I ‡ II of fruit growth (including the initial(More)
It is a well know result that the geometry of pan and tilt (perspective) cameras auto-calibrate using just the image information. However, applications based on panoramic background representations must also compensate for radiometric effects due to camera motion. In this paper we propose a methodology for calibrating the radiometric effects inherent in the(More)
In this paper we propose a methodology for minimizing the variance of a cube (mosaicked) representation of a scene imaged by a pan-tilt camera. The minimization is based on the estimation of the vignetting image distortion, using the pan and tilt degrees of freedom instead of color calibrating patterns. Experiments with real images show that variance(More)
This paper presents an analysis of uncertainty in the calibration of a network of cameras. A global 3D scene model, acquired with a LIDAR scanner, allows calibrating cameras with non overlapping fields of view by means of the DLT-Lines algorithm. Once the projection matrix is computed for each camera, error sources are propagated to compute estimates of(More)
Although there are intrinsic advantages of using pan-tilt-zoom cameras their application in automatic surveillance systems is still scarce. The difficulty of creating background models for moving cameras and the difficulty of keeping fitted pose and optical geometrical projection models are key reasons for the limited use of pan-tilt-zoom cameras. Geometric(More)
In this paper we approach the problem of calibrating topologically a discrete camera mounted on a robotic pan-tilt basis. In particular this work is focused in choosing the coordinate system of the camera consistently with the basis. The topological calibrating methodology of the sensor is based on multidimensional scaling (MDS). The choice of the(More)
3D metric data of environmental structures is nowadays present in many information sources (maps, GIS) and can be easily acquired with modern depth sensing technology (RGBD, laser). This wealth of information can be readily used for single view calibration of 2D cameras with radial distortion, provided that image structures can be matched with the 3D data.(More)
In this paper we propose a methodology for normalizing the images gains in a mosaicked representation of a scene imaged by a pan-tilt camera. The normalization is based on assuming that one image has unit gain and then estimating, and filtering, the relative gains of all the other images, using the known geometry of the pan and tilt camera to find(More)
  • 1