Volume 1 Issue 2
Authors: Xuezhu Lin; Guohua Cao; Lijuan Li; Xin Yang
Abstract: In the three-dimensional measurement, when the data are processed, the alignment of point clouds with CAD model is an indispensable step. Only by this alignment can the CAD model coordinate system be consistent with the measurement coordinate system, therefore, the measured values have comparability. An in-depth study has been carried out on the alignment methods and techniques according to CAD model and point clouds in CATIA, and a series of alignment methods and techniques have been provided, such as compass method, aligned sphere method, vector matching method, etc. For complex CAD model alignment, one or several appropriate ways can be chosen to achieve alignment work after actual measurement, in order to improve the alignment accuracy. These methods and techniques, for data processing work of digital three-dimensional measurement, have some practical engineering guidance significance.
Keywords: Rapid Alignment; Points Cloud; Three-dimensional CAD Model; CATIA
Authors: Zhaohua Liu; Yuxia Yang; Jingyu Yang
Abstract: Aiming at the degraded image quality in bad weather, a novel haze removal method for single image based on dark channel prior is firstly introduced. Then these disadvantages of initialized method are analyzed and improved, a tolerance mechanism is introduced to deal with the dark channel prior ineffective zones, a fast edge-preserving interpolating algorithm of atmosphere transmission based on guided image filter is proposed to overcome time-consuming problem of soft matting algorithm, a Wallis filter is used to improve the intensity of result image. And to improve the de-hazing efficiency more, a GPU-CPU cooperating scheme is designed and corresponding fine granularity parallel computing of de-hazing is realized based on integral image and box filter through GPU. At last, three aerial images are processed using GeForce 9500 GT card to validate the proposed method.
Keywords: Dark Channel Prior; Guided Filter; Wallis Filter; GPU; Integral Image
Authors: Wani Rashid A.; Khairkar V. P.; Jalindar
Abstract: Urbanization, the process of becoming urban, is the key factor responsible for changing the socio-economic conditions of the area bringing changes in land use/land cover which ultimately lead to loss of agricultural land, marshy land and water bodies through encroachments etc. India is one of the world’s fastest growing urban countries and an effort has been made in this paper to analyze the urban expansion of Ahmadnager from 1974 to 2012. In the present study, toposheet no. 47I/12, 47I/16 for the year 1974 and Satellite Imagery-LISS-III 2008 and Google Image 2012 are used. The study area was classified into built-up, vegetation, water bodies, fallow land and barren land. Finally, change process of Ahmadnager built up area over 1974-2012 was determined using overlay analysis. Built up area has increased over 7 times during this period. Also ward wise land use/land cover change has been quantified in addition to hospital information (medical) database for emergency services and health planning has been generated.
Keywords: Land Use/ Land Cover; Urban Expansion; Satellite Imagery; Medical Database