浮游藻类细胞微流控-显微图像形变校正方法

Microfluidic-microscopic image deformation correction method for planktonic algal cells

流式细胞显微图像分析法是水体浮游藻类自动鉴别的重要发展方向,快速进样条件下细胞显微图像将产生形变,影响浮游藻类自动鉴别准确率。本文基于搭建的浮游藻类微流控-显微成像实验系统,通过对不同进样流速下藻类细胞显微形变和图像清晰度的分析,研究了流速对显微成像形变的影响规律。分析基于卷帘快门拍摄运动物体产生形变原理,提出了单向偏移像素的图像形变校正方法,并与藻类细胞静态条件下获取的图像进行了对比分析。实验结果表明:静态条件下,湖生卵囊藻细胞的图像长宽比及清晰度均值分别为1.16和116.53;动态进样过程中,随着流速增大细胞图像形变(长宽比)逐渐增大、清晰度降低;95μL/min进样流速下,校正前后细胞图像长宽比均值分别为1.35和1.26,形变离散程度由校正前的0.33降至0.1,与静态细胞形态接近且校正前后图像清晰度基本不变。本文研究结果为提升水体浮游藻类细胞自动鉴别准确率提供了依据。

Flow cytomicrographic analysis is an important development in the automatic identification of planktonic algae in a water column,but the accuracy of this process is affected by the deformation of microscopic images under rapid injection conditions.Based on a microfluidic-microscopic imaging system for planktonic algae,the effects of flow rate on the deformation of microscopic images were investigated by analyzing the deformation of algal cells and image clarity at different injection flow rates.Based on the principle of deformation caused by photographing a moving object using a rolling shutter,a method of image deformation correction with unidirectional offset pixels is proposed and analyzed by comparing its results with images acquired under static conditions of algal cells.The experimental results showed that the average aspect ratio and sharpness of L values for oocystis cell images under static conditions were 1.16 and 116.53,respectively;during the dynamic injection process,the deformation(aspect ratio)of the cell images gradually increased and the sharpness decreased as the flow rate increased;the average values of aspect ratio before and after correction were 1.35 and 1.26 respectively at 95μL/min injection flow rate,and the dispersion of deformation decreased from 0.33 before correction to 0.1.The results are close to that of static cell morphology and the image sharpness is basically same.The results provide a method for improving the accuracy of the automatic identification of planktonic algal cells in a water column.