基于自适应概率PCA的植物叶片彩色图像修复
作者:
作者单位:

作者简介:

通讯作者:

中图分类号:

基金项目:

北京市自然科学基金项目(4172034)和“十二五”国家科技支撑计划项目(2015BAH28F0103)


Adaptive Probabilistic PCA Method on Color Image Inpainting and Its Application in Plant Leaf
Author:
Affiliation:

Fund Project:

  • 摘要
  • |
  • 图/表
  • |
  • 访问统计
  • |
  • 参考文献
  • |
  • 相似文献
  • |
  • 引证文献
  • |
  • 资源附件
  • |
  • 文章评论
    摘要:

    植物叶片图像的采集过程中,由于自然环境或成像条件的影响,特别是夜间,采集到的图像大多带有椒盐噪声,造成图像质量下降。很多植物叶片含有丰富的叶脉,被噪声污染不利于后续的表型分析、图像分割等。椒盐噪声密度较小时,中值滤波降噪效果较好,但在噪声污染严重时滤波方法也无法有效去噪。针对这一问题,提出了基于概率PCA的图像修复模型。一幅光滑的不含噪图像通常可认为服从高斯分布,概率PCA能有效地提取描述这幅图像中的主要信息,通过估计模型参数重构因噪声引起的数据缺失,从而达到图像修复的目的。但是当噪声的缺失像素点聚集在叶脉上时,直接用概率PCA修复会出现明显的边界效应,因此本文先基于树的叶脉进行追踪,再对叶脉进行概率PCA修复,然后再基于整幅图像利用概率PCA模型修复,迭代次数根据修复后图像的PSNR值自适应地选择。为了验证所提出的模型的修复性能,进行了与常用滤波方法的对比试验。试验结果表明:去噪后的图像PSNR值比使用均值滤波高出6dB左右,比使用维纳滤波高出9dB左右,比使用高斯滤波高出7dB左右,比使用中值滤波高出1dB左右,并且在结构相似性上采用本文算法去噪后的图像与原始图像的相似度最高。因此,将概率PCA模型应用于植物叶片彩色图像修复是可行的、有效的,为其后续的图像处理提供了技术支持。

    Abstract:

    Because of the influence of nature meteorological condition and background environment during the acquisition of the plant leaf image, the image degradation is always unavoidable with the salt and pepper noise. The image of plant leaf is generally characterized by rich textures and welldefined edges. It is unfavorable to the subsequent processing of color image with noise pollution. Although there are several filtering methods such as average filtering, wiener filtering, gauss filtering and median filtering, they do not satisfy the requirment on effective repairation and texture reservation of image. Consequently, to repair the image successfully with the textural details preserved and the edges clear, a new model for color image inpainting was proposed and called adaptive probabilistic PCA method. The procedure of the proposed model included 2 steps.After the leaf vein was identified and tracked based on tree, the vein inpainting was conducted by the probabilistic principal component analysis (PPCA) model, in which the iterations were adaptively selected according to the PSNR value of the restored images. To evaluate the effectiveness of the proposed model, a 3-step simulation test was invloved, and the evaluation criteria based on SNR and structural similarity image measurement(SSIM) was used to measure the degree of image distortion and similarity between the processed and the original image. Firstly, to determine the optimal iterations of the PPCA model, the inpainting results in different iterations were compared. Secondly, to test the image inpainting ability, the polluted images are simulated with different levels of noise. Finally, the proposed model had some comparison with the conventional filtering methods. The experiments showed that the iterations about 550 were appropriate while using the PPCA model for image inpainting. The restored image obtained by the proposed model was less residual noise and clearer textures than other filtering methods visually. The PSNR value of restored image was 26.8199dB, which was higher than using the wiener filtering, gauss filtering, average filtering and median filtering, by 9dB,7dB,6dB and 1dB, respectively. It was higher than the PSNR value of the noisy image by 14.48dB. The SSIM value of restored image was 0.9557, which was the largest among the above-mentioned methods. It indicated that the restored image using the proposed model was closer to the original image in the brightness, contrast and structure aspects. It could provide technical support to the subsequent processing of the color image.

    参考文献
    相似文献
    引证文献
引用本文

郭书君,李丽,梅树立.基于自适应概率PCA的植物叶片彩色图像修复[J].农业机械学报,2017,48(s1):147-152, 165.

复制
分享
文章指标
  • 点击次数:
  • 下载次数:
  • HTML阅读次数:
  • 引用次数:
历史
  • 收稿日期:2017-07-10
  • 最后修改日期:
  • 录用日期:
  • 在线发布日期: 2017-12-10
  • 出版日期: