光照与物镜距离对采集玉米籽粒图像影响的研究

Research of the effects of light and lens distance ontaking pictures of corn grain

设计了具有主光源、辅助光源，物镜距离可调的玉米籽粒图像采集实验箱，应用数码相机采集实验箱载物台上玉米籽粒的图像。以玉米籽粒形状特征、颜色特征为对象，分析同一物镜距离下辅助光源的放置方式与强度对图像采集的影响，光源确定的情况下物镜距离对图像采集的影响。结果表明：闪光灯留下的光斑影响特征提取，辅助光源平行和垂直放置、物镜距离在26～31cm范围内较佳。

This article introduced an experiment box for taking pictures of corn grain, including main light source, auxiliary light source, a lifter which could adjust the distance of the object to the camera lens and a stage whieh held the corn grain. Pictures of corn grain were collected by digital camera. Taking the characteristics of shape and color as the research object, this paper researched how to place the auxiliary light source and how to set the light intensity when the lifter was fixed, and how to set the distance when determining the light souree. Experimental results showed that, the light spot which came from camera flash affectted feature extraction, the auxiliary light source should be placed in the form of parallel or vertical, and the distance of object to camera lens within the scope of 26-31 cm was better.