光学学报, 2016, 36 (4): 0411002, 网络出版: 2016-04-05
光电测量设备图像高频频谱对主观评价的影响
Influence of High Frequency Spectrum of Photoelectric Measurement Equipment Images to the Subjective Evaluation
成像系统 光电测量设备 高频频谱 调制传递函数 低通滤波器 主观评价 image processing photoelectric measurement equipment high frequency spectrum modulation transfer function low-pass filter subjective evaluation
摘要
分析了光电测量设备图像质量评价研究过程中,图像频谱高频分量对图像质量人眼主观评价影响的途径和解决措施。对清晰图像通过Butterworth 低通滤波器在频域进行了低通滤波,然后利用滤波图像分析了图像高频频谱对人眼主观感受的影响。用斜狭缝法对离焦成像系统的调制传递函数(MTF)进行了测试,并对相应离焦状态的模糊图像进行了主观评价。对不同像元尺寸相机获取的图像进行了频谱分析和图像评价,实验结果表明,图像频谱高频分量比例增多,图像具有更丰富的细节和更高的清晰度,准确调焦及采用小像元尺寸相机是提高光电测量设备图像质量的重要因素。给出了影响光电测量设备图像质量的其他因素,并提出了改进措施。
Abstract
In the course of studying the image quality assessment of photoelectric measurement equipment, the influence approach of the high frequency component of image spectrum to image quality subjective evaluation of the human eye and solving measures are analyzed. The clear image is processed by Butterworth low-pass filter in frequency domain. Then the influence of the high frequency part of image spectrum to the human eye subjective feeling is analyzed by filtering the image. The modulation transfer function (MTF) of defocus imaging system is measured by using the canted slit method, and the corresponding defocus blurred images are evaluated subjectively. Spectrum analysis and image evaluation of images acquired by the cameras with different pixel sizes are carried out. Experimental results indicate that the images have more high frequency component, richer details and higher clarity. Focusing exactly and capturing by camera with small pixel size are important measures to improve the image quality of the photoelectric measurement equipment. Other influencing factors and improving methods are proposed and the improving measures are put forward.
张宁, 沈湘衡, 叶露, 宋莹. 光电测量设备图像高频频谱对主观评价的影响[J]. 光学学报, 2016, 36(4): 0411002. Zhang Ning, Shen Xiangheng, Ye Lu, Song Ying. Influence of High Frequency Spectrum of Photoelectric Measurement Equipment Images to the Subjective Evaluation[J]. Acta Optica Sinica, 2016, 36(4): 0411002.