Study on feature extraction and filling-in process in visual system

视觉系统特征提取与填充过程研究

• 批准号: 13650459
• 负责人: TSUKADA Akira
• 金额: $ 1.73万
• 依托单位: Toyama National College of Maritime Technology (2002-2003)University of Toyama (2001)
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 2001
• 资助国家: 日本
• 起止时间: 2001 至 2003
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-13650459/
• 关键词: adaptation; fovea; high dynamic range image; 高ダイナミックレンジ; 明るさ知覚

(1) We tried to apply the model which can explain some brightness illusions to the real image in order to examine why visual illusion occurs in the visual system. As a result, it is suggested that the mechanism which produces the brightness illusion is concerned in focusing and fusion of the binocular retinal images.(2) Retinal cones play an important role in light adaptation. To understand the light adaptation, it is necessary to consider characteristics of the cone. The light intensity-response curve for the cone is a S-shape curve. We employ this curve to enhance a contrast of digital images. This method can improve some problems of previous enhance methods.(3) Overall (average) adaptation and local adaptation exist in human visual system. In addition, a physiological experiment suggests that the midrange adaptation may occur in human visual system. The present study was carried out to examine the existence and the characteristics of the midrange adaptation by comparing subjective brightness of two spots. The results indicate that the midrange adaptation occurs when a step change in luminance exists on the fovea, but not when it exists out of the fovea.(4) In order to understand that the subjective circle is brighter than the background, we measured the perceived brightness of the part which faces line end and part which faces the parallel side of the stripe. With decreasing line interval, the perceived brightness of the line end (parallel side) is brighter (darker).(5) We apply the midrange adaptation and S-shape curve of the cone to high dynamic range images (over 60dB). Both contrast of bright region and dark region was improved.

(1)我们试图将能够解释某些亮度错觉的模型应用到真实图像中，以检验视觉系统中为什么会出现视觉错觉。由此推测亮度错觉的产生机制与双眼视网膜图像的聚焦和融合有关。(2)视网膜锥体在光适应中发挥着重要作用。要了解光适应，有必要考虑锥体的特性。锥体的光强响应曲线是S形曲线。我们利用这条曲线来增强数字图像的对比度。该方法可以改善以往增强方法的一些问题。(3)人类视觉系统存在整体(平均)适应和局部适应。此外，生理实验表明，人类视觉系统可能发生中频适应。本研究通过比较两个点的主观亮度来检验中频适应的存在性和特征。结果表明，当中央凹内存在亮度阶跃变化时，会发生中频适应，但当亮度阶跃变化存在于中央凹之外时，则不会发生。（4）为了理解主观圆比背景更亮，我们测量了感知圆面向线端的部分和面向条纹的平行边的部分的亮度。随着线间隔的减小，线端（平行边）的感知亮度变得更亮（更暗）。（5）我们将锥体的中频自适应和S形曲线应用于高动态范围图像（超过60dB）。亮区和暗区的对比度均得到改善。

项目成果

塚田 章: "ストライプ図形の内部および外部の明るさ知覚"映像情報メディア学会誌. 55・11. 1515-1519 (2001)

Akira Tsukada：“条纹形状的内部和外部亮度感知”图像信息和媒体工程师研究所杂志55・11（2001）。

TSUKADA, Akira: "Model of brightness illusion of human visual system"Proc.of 2001 Int.Tech.Conf.on Circuits/Systems, Computers and Communications. 1. 763-766 (2001)

Tsukada, Akira：“人类视觉系统的亮度错觉模型”Proc.of 2001 Int.Tech.Conf.on Circuits/Systems, Computers and Communications。

ZO, Sachiko: "Compression method for high dynamic range Images using light adaptation"Proc.of the Joint Conference of Hokuriku Capters of Institute of Electrical Engineers. 49 (2002)

ZO，Sachiko：“使用光适应的高动态范围图像压缩方法”，电气工程师学会北陆Capters联合会议论文集。

岩瀬絵里香: "網膜の錐体密度を考慮した高ダイナミックレンジ画像圧縮法"平成15年度電気関係学会北陸支部連合大会講演論文集. 322 (2003)

Erika Iwase：“考虑视网膜锥体密度的高动态范围图像压缩方法”2003年电气工程学会北陆分会会议记录322（2003）。

岩瀬絵里香: "網膜の不均一性を考慮した高ダイナミックレンジ画像圧縮"平成15年度日本エム・イー学会北陸支部大会講演論文集. 5-6 (2003)

Erika Iwase：“考虑视网膜异质性的高动态范围图像压缩”日本 EM 学会 2003 年北陆分会会议记录 5-6 (2003)。