Optimized Design And Realization Of The Footprint Sample Acquisition Systems

The development of modern science and technology,such as big data,cloud computing,and internet of things,provides a solid foundation and objective condition for promoting the intellectualization of criminal investigation technology of public security organs.Strengthening information collection and aggregation and empowering criminal investigation with data has become a very important fundamental work.The footprint is a kind of trace material evidence which achieves a high extraction rate of investigations for the crime scene.It is also an important type of data for public security organs to carry out the collection,inspection,and identification of basic information of personnel.To ensure efficient,accurate,and normative footprint sample is of great significance for criminal detection,which makes it particularly important to optimize the previous equipment and improve its performance.Based on the background,this thesis focuses on the study of optimized design and realization of footprint sample acquisition systems to solve the problems existing in the current system such as image noise,glass fogging,and fault detection.First of all,the structure and principle of the footprint sample acquisition system is introduced and the problems and improvement requirements in the practical application is analyzed.To meet the requirement of denoising the footprint sample image,the wavelet transform method with an improved threshold is adopted,which is proved to be better than the traditional wavelet transform method by simulation results.The denoising function is developed by Visual C++6.0 and Open CV.For the demand of quality evaluation for footprint images,the footprint image quality evaluation system is analyzed and designed.Further,the design and implementation of automatic defogging and automatic fault diagnosis function of the acquisition system are completed.The automatic defogging module is realized by automatic temperature control based on STM32 microcontroller and PID algorithm technology with using a DS18B20 temperature sensor and electric heating glass.Fault detection for the LED light,camera,and related devices is realized by the combination of the control circuit with STM32.The automatic fault diagnosis function is realized by using OLED to display fault information and buzzer to alarm with the help of I2 C mode communicating with STM32.Finally,the test plan of the system is designed to experimentally test the functions of denoising,automatic defogging,and automatic fault diagnosis.The experimental results show that the optimization design of the footprint sample acquisition systems meets the expected design objectives and performance requirements.The optimized and upgraded system scheme is more in line with the actual use needs of case-handling personnel,and significantly improves the collection quality and maintenance efficiency of the footprint sample acquisition system.Thus,the effectiveness and check rate of footprint information is strengthened,and the applicable efficiency of the footprint in the investigations of criminal cases is further improved.