CAJ | 학술논문

现有图像清晰度评价函数在对ICF微靶装配体图像的评价过程中，由于不同零件图像对比度的变化，评价函数极易失去其理想曲线特性，导致聚焦精度降低甚至调焦过程失败。针对这一问题，在分析离焦图像模糊原因的基础上，得出离焦图像究其本质为图像结构变化失真。利用Zernike矩具有描述图像结构特征这一特性，提出一种新的针对微靶装配体图像的清晰度评价函数。评价函数由图像不同阶Zernike矩的线性组合构成，通过调节权重系数来实现微靶装配体不同零件图像的清晰度评价。实验结果表明：相较于现有的评价函数，新的评价函数在对微靶装配体图像评价过程中保持了函数的理想曲线特性，尤其是针对低对比度图像，其在灵敏度和抗噪性方面具有明显优势。
현유도상청석도평개함수재대ICF미파장배체도상적평개과정중，유우불동령건도상대비도적변화，평개함수겁역실거기이상곡선특성，도치취초정도강저심지조초과정실패。침대저일문제，재분석리초도상모호원인적기출상，득출리초도상구기본질위도상결구변화실진。이용Zernike구구유묘술도상결구특정저일특성，제출일충신적침대미파장배체도상적청석도평개함수。평개함수유도상불동계Zernike구적선성조합구성，통과조절권중계수래실현미파장배체불동령건도상적청석도평개。실험결과표명：상교우현유적평개함수，신적평개함수재대미파장배체도상평개과정중보지료함수적이상곡선특성，우기시침대저대비도도상，기재령민도화항조성방면구유명현우세。
During the process of evaluating ICF micro-target image with the current image definition evaluation function, owing to the changes in image contrast of different components of micro-target, the evaluation function may lose its ideal curve characteristics easily. This may not only result in the decrease of focus accuracy but also, in some cases, the failure of the entire focusing process. Based on the analysis of the causes for the blurring defocused image, we discovered that the primary reason for defocused image was structural distortion. With the characteristic of Zernike moment of descri-bing the image structure in mind, we propose a new function for evaluating the image definition of micro-target. The new evaluation function is consisted of Zernike moments weighting of different steps, and it is realized through the evaluation of image contrast for micro-targets of different defini-tions by regulating the weight coefficient. We confirm that the new evaluation function maintains the ideal curve characteristics during the process of evaluating the micro-target images compared to the current evaluation function. In the condition of low contrast, however, the new approach holds a distinct advantage in terms of sensitivity and noise immunity.