Non-reference Quality Assessment of Dermoscopy Images with Defocus Blur and Uneven Illumination Distortion
-
摘要: 皮肤镜图像的采集质量直接影响后续的分析诊断结果.针对皮肤镜图像在采集过程中可能出现的散焦模糊和光 照不均两种类型的失真,提出了一种有效的无参考图像质量评价算法. 通过频率特性分析我们发现,散焦模糊主要 影响离散余弦变换(Discrete cosine transform,DCT)后的直流分量,而光照不均则主要影响第一交流分量.针对该特性,论文在频率域设计质量评价模型,首先将散焦模糊与光照不均两种失真成功分离,进而分别计算失真程度,给出评价指标.实验结 果表明,本文提出的算法既可以对散焦模糊或光照不均单一失真类型的皮肤镜图像进行质量评价,也可以对两种失真类型 同时存在的复杂皮肤图像进行评价,给出的评价结果稳定客观、互相独立,且与主观评价结果相一致.Abstract: The quality of dermoscopy images will impact the subsequent segmentation and analysis results. An efficient non-reference image quality assessment algorithm is proposed when defocus blur exists in an image with uneven illumination. The discrete cosine transform (DCT) is carried out and the frequency characteristic is deeply analyzed for dermoscopy images. It is found that defocus blur mainly affects the direct current (DC) component while uneven illumination mainly affects the first alternating current (AC) component. According to this finding, a quality assessment model is proposed in the frequency domain. Defocus blur signal is successfully separated from uneven illumination signal firstly, and then two metrics respectively for defocus blur and uneven illumination signals are calculated. Experiment results show that the proposed metrics can not only evaluate dermoscopy images with the single type of distortion caused by either defocus blur or uneven illumination, but also evaluate the ones with both of them at the same time. The evaluation results are stable, objective, independent, and consistent with the subjective evaluation results.
-
[1] [3] Wang Z, Bovik A C. Image quality assessment: from error visibility to structural similarity. IEEE Transactions on Image Processing, 2004, 13(4): 600-612 [2] [4] Wang Z, Sheikh H R, Bovik A C. No-reference perceptual quality assessment of JPEG compressed images. In: Proeedings of the 2002 IEEE International Conference on Image Processing. New York, USA: IEEE, 2002. 477-480 [3] [5] Sheikh H R, Bovik A C, Cormack L. Blind quality assessment of JPEG2000 compressed images using natural scene statistics. In: Proceedings of the 2003 IEEE Asilomar Conference on Signals, Systems, and Computers. California, USA: IEEE, 2003. 1403-1407 [4] [6] Saad M A, Bovik A C, Charrier C. DCT statistics model-based blind image quality assessment. In: Proceedings of the 2011 IEEE International Conference on Image Processing. Brussels, Belgium: IEEE, 2011. 3093-3096 [5] [7] Marziliano P, Dufaux F, Winkler S, Ebrahimi T. A no-reference perceptual blur metric. In: Proceedings of the 2002 International Conference on Image Processing. New York, USA: IEEE, 2002. 57-60 [6] [8] Wang X, Tian B F, Liang C. Blind image quality assessment for measuring image blur. In: Proceedings of the 2008 Congress on Image and Signal Processing. Sanya, China: IEEE, 2008. 467-470 [7] [9] Lu C. No-reference image blur measurement based on wavelet high-frequency domain analysis. In: Proceedings of the 2010 International Conference on Information Science and Engineering. Hangzhou, China: IEEE, 2010. 3844-3846 [8] Chen M J, Bovik A C. No-reference image blur assessment using multiscale gradient. EURASIP Journal on Image and Video Processing, 2011, 2011(3): 1-11 [9] Wei W Y, Li Z M, Zhang G Q. Novel fuzzy clustering-base image segmentation with simultaneous uneven illumination estimation. Information Technology Journal, 2011, 10(3): 607-610 [10] Leong F J W M, Brady M, McGee J O D. Correction of uneven illumination (vignetting) in digital microscopy images. Journal of Clinical Pathology, 2003, 56(8): 619-621 [11] Deng Y, Dai Q H, Zhang Z K. Graph Laplace for occluded face completion and recognition. IEEE Transactions on Image Processing, 2011, 20(8): 2329-2338 [12] Deng Y, Dai Q H, Liu R S, Zhang Z K, Hu S Q. Low-rank structure learning via nonconvex heuristic recovery. IEEE Transactions on Neural Networks and Learning Systems, 2013, 24(3): 383-396 [13] Meng Ru-Song, Cai Rui-Kang, Zhao Guang, Cheng Xiao-Xiang, Jiang Zhi-Guo, Zhou Fu-Gen, Yang Ze-Sheng, Chen Jin. Study on analysis technology of polari-light skin scope digital image and application in diagnosing pigment injured skin. Chinese Journal of Stereology and Image Analysis, 2006, 11(2): 122-126 (孟如松, 蔡瑞康, 赵广, 成晓湘,姜志国,周付根,杨泽生, 陈进. 偏振光皮肤镜数字图像分析技术的研究及在色素性皮损诊断中的探讨. 中国体视学与图像分析,2006, 11(2): 122-126) [14] Rao K R, Yip P. Discrete Cosine Transform: Algorithms, Advantages, Applications. Boston: Academic Press, 1990 [15] Zhou Jing-Chao, Dai Ru-Wei, Xiao Bo-Hua. Overview of image quality assessment research. Computer Science, 2008, 35(7): 1-4 (周景超, 戴汝为, 肖柏华. 图像质量评价研究综述. 计算机科学, 2008, 35(7): 1-4)
点击查看大图
计量
- 文章访问数: 1891
- HTML全文浏览量: 72
- PDF下载量: 1367
- 被引次数: 0