A fully automatic registration approach based on contour and SIFT for HJ-1 images

To achieve a fully automatic registration between HJ-1 CCD images and HJ-1 infrared images is a difficult task as it must deal with the varying illuminations and resolutions of the images,different perspectives,and the local deformations within the images.In this paper,aimed at those registration issues,a fully automatic registration approach based on contour and SIFT is proposed.The registration technique performs a pre-registration process using contour feature matching algorithm that decides the overlapping region between a reference image and an input image.Once the coarse regions are obtained,it performs a fine registration process based on SIFT detector and a local adaptive matching strategy.In the fine registration process,image blocking theory is used,which not only speeds up the features extraction and matching,but also makes the matching point pairs distributed uniformly in images,and further improves the accuracy of input image rectification.Experiments with visible images and infrared images from HJ-1A/B demonstrate the efficiency and the accuracy of the proposed technique for multisource remote sensing images registration.

A study of projections for key point based registration of panoramic terrestrial 3D laser scan

This paper surveys state-of-the-art image features and descriptors for the task of 3D scan registration based on panoramic reflectance images.As modern terrestrial laser scanners digitize their environment in a spherical way,the sphere has to be projected to a two-dimensional image.To this end,we evaluate the equirectangular,the cylindrical,the Mercator,the rectilinear,the Pannini,the stereographic,and the z-axis projection.We show that the Mercator and the Pannini projection outperform the other projection methods.

An improved approach for the production of satellite-based geospatialreference imagery

An innovative and practical satellite image product is described that is ideal for applications in Northern Canada because of its wide area coverage and mappingquality features.This product is generated from a new procedure developed at the Canada Centre for Remote Sensing(CCRS)for processing Landsat 7 imagery,and by extension,imagery from other Earth Observation satellites.By working with multiple satellite passes,each containing the equivalent of multiple scenes,the new procedure could dramatically reduce the turn-around time for generating georeferenced image products,and also increase their geometric and radiometric accuracy compared to those produced by the current methods.The objective of the process has been to generate satellite image mosaics covering large areas(e.g.>500000 km^(2))with uniformly distributed errors at sub-pixel resolution.The paper discusses the theoretical basis of a photogrammetric adjustment for satellite imagery and the results obtained from several tests.The process is generic,involving a sensor model,a satellite orbit model and ground control information;thus it may be easily adapted to any satellite that allows for repeat coverage with overlapping paths.By performing an adjustment to correct the satellite position and attitude data prior to the production of orthoimage products,it is possible to create a mosaic with a single resampling process which minimises both the radiometric and geometric resampling artifacts.The results from three separate tests are presented,along with a discussion of the procedures that were followed in each case.All three tests have successfully demonstrated that sub-pixel sample size errors may be consistently obtained over large areas.A by-product process developed to support the measurement of ground control point coordinates for the satellite adjustment was the automatic matching of geographic features such as lakes and islands in vector data format.This has been a significant development in that it has eliminated manual intervention in the measurement of these features in the imagery,allowing the ground control for entire passes containing several scenes to be obtained in minutes instead of hours.