利用X射线二维图像的每个灰度值的负指数与厚度成正比的关系,在实验参量设置一定的条件下,计算出苹果的衰减系数;建立苹果体积数学预测模型,计算出苹果的体积。实验结果表明,X射线能量衰减与苹果厚度符合指数规律,回归相关系数R2μ=0.9932,衰减系数m=0.0114;完整苹果真实体积与计算体积相关系数R2ν=0.9809,预测相关系数r2=0.9203,因此模型具有良好稳健性和预测性。

By using the direct ratio between the minus exponential of every gray value of two-dimensional X-ray image and the thickness of the slice, the attenuation coefficient of the apple was calculated on the condition of the invariable experimental parameters. The mathematic model to predict apple cubage was established, and the cubage of the apple was predicted. The result of the experiment testified the exponential relation between the attenuation of the X-ray energy and the thickness of the apple slice, the regression correlation coefficients for calibration is 0.9932, and the average attenuation coefficient is 0.0114. The regression model was obtained with the correlation coefficient for calibration and prediction coefficient of 0.9809 and 0.9203, respectively between the actual value and predicted value of apple cubage. The mathematic model could calculate the cubage of the apple reliably and credibly.