An Active Hyperspectral Image System Based On LED Illumination

Hyperspectral imaging(HSI)technology can simultaneously obtain both spectral and spatial information.According to the imaging mode,it can be divided into passive HSI and active HSI technology.The active HSI technology has some obvious advantages,such as avoiding the environmental effects,eliminating natural light limitations and removing shadows.It has been widely used in agriculture,food,medical treatment and other fields.In the paper,an active HSI system based on LED illumination is designed and implemented.The main work is as follows:(1)hardware design:The active hyperspectral imaging system is designed and built.The system is mainly composed of light source module and image acquisition module.The light source module focus on the selection of LED,which is used to form a spectral tunable array.The beam homogenization scheme is designed to adjust the intensity distribution of LED light source.CMOS color image sensor is chosen to collect image.(2)system calibration and evaluation: The suitable system calibration algorithm and evaluation scheme are designed.The goal of system calibration is to reconstruct the hyperspectral image cube.The performance of our system is evaluated by comparing the experimental results of our system with GaiaSorter Hyperspectral System.(3)application: The active HSI system based on LED illumination is applied to recognize the categories of food in intelligent fridge.Based on SVM algorithm,the recognition accuracy of experiments is about 95%.In the paper,the spectral detection range of the proposed system is 441-662 nm,and the spectral resolution is about 10 nm.The image resolution is 3870 pixels × 5796 pixels,and the image bit resolution is 14 bit.The evaluation of system proved that the proposed system can obtain the hyperspectral image of the target object successfully.Based on the proposed system,the high accuracy rate of food recognition can be acquired in intelligent refrigerator.The innovation of this thesis is as follows: 1)An active HSI system based on LED illumination is designed.A series of narrow-band LED with different peak wavelength is used to form a spectral tunable array.The system has the advantage of low cost and simple structure,which can be used to split light without traditional splitter elements.2)Color Image Sensor can increase the amount of information and spectral response range.