Research Of Virtual Rebuilding Techniques For The Criminal Scenes

The survey of the criminal scenes means the personnel makes spot survey, investigation and record on the time, place, people, accidents and contents related to the crime. It is significant to find out the character of the case, collect the evidence of the criminal, analyze the characteristic of the criminal and confirm the direction of the detection, which is the starting point of detection and also an important part of police criminal detection. It is the traditional methods to reflect information of the scene through deposition, field images, field photos, field videos, different survey conclusions and oral descriptions of detection personnel. These methods contain subjectivity and localization of the information and the amount of information acquired differs by different person.Nowadays, computer science and engineering technology develops rapidly and has been applied in many professions. It is an urgent affair of how to combine it to scene detection, which can improve the information and science levels of scene detection. This paper encircled the characteristics and requirements of scene detection of police department, presented a virtual rebuilding method based on IBR (Image Based Rendering), which associated with virtual reality and image processing. And made emphases research on some key techniques of panorama image creation.Firstly, it made a universe model of the creating process of scene panorama image and divided the whole issue to five modules, which were scene fisheye image acquisition, fisheye lens distortion correction, pre-processing of the scene image, scene image matching after pre-processing and scene image smoothing. Secondly, it built research sub-models separately of each module, which made each segment of research process coincide the characteristic of scene circumstance and carry through in the frame of criminal scene virtual rebuilding.It had made deep research of the constitution and imaging principle of fisheye lens and made criterion of detail technique during image acquisition on the character of scene circumstance and fisheye lens and the demand of issues investigation.It summarized some methods of image pre-processing technique systematically. Histogram and mid-value filtering were applied to pre-process the scene image, which developed the sight effect and reduced the influence of noises.A precise matching algorithm was put forward against the image matching segment of criminal scene rebuilding. The characteristic points extracted by the algorithm distributed equally, stably and credibly. Although the matching speed did not fast, it matched precisely and stably. It was very suitable on the criminal scene image matching where need general real time quality, but high accuracy. It was also the main innovate point in this paper.After image matching completed, we adopt a type of fade in fade out algorithm on the images to smooth and achieved preferable results.