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利用广义归一化变换的图像密度建模

Density Modeling of Images using a Generalized Normalization Transformation
课程网址: http://videolectures.net/iclr2016_balle_density_modeling/  
主讲教师: Johannes Ballé
开课单位: 纽约大学
开课时间: 2016-06-15
课程语种: 英语
中文简介:
我们引入了一种参数非线性变换,它非常适合于对自然图像中的数据进行高斯化。数据进行线性转换,然后每个组件通过池活动度量进行标准化,通过对整流和指数化组件的加权和和和常数求幂来计算。我们在自然图像数据库上优化全变换的参数(线性变换,指数,权重,常数),直接最小化响应的负熵。优化的转换实质上高斯化的数据,实现一个显著较小的相互信息转换组件之间比替代方法,包括ICA和径向高斯化。该变换是可微的,可以有效地反演,从而得到图像上的密度模型。我们表明,该模型的样本在视觉上类似于自然图像补丁的样本。我们演示了该模型作为先验概率密度的使用,可用于去除附加噪声。最后,我们展示了转换可以级联,每一层都使用相同的高斯化目标进行优化,从而提供了一种优化深度网络架构的无监督方法。
课程简介: We introduce a parametric nonlinear transformation that is well-suited for Gaussianizing data from natural images. The data are linearly transformed, and each component is then normalized by a pooled activity measure, computed by exponentiating a weighted sum of rectified and exponentiated components and a constant. We optimize the parameters of the full transformation (linear transform, exponents, weights, constant) over a database of natural images, directly minimizing the negentropy of the responses. The optimized transformation substantially Gaussianizes the data, achieving a significantly smaller mutual information between transformed components than alternative methods including ICA and radial Gaussianization. The transformation is differentiable and can be efficiently inverted, and thus induces a density model on images. We show that samples of this model are visually similar to samples of natural image patches. We demonstrate the use of the model as a prior probability density that can be used to remove additive noise. Finally, we show that the transformation can be cascaded, with each layer optimized using the same Gaussianization objective, thus offering an unsupervised method of optimizing a deep network architecture.
关 键 词: 自然图像; 线性变换; 数据转换
课程来源: 视频讲座网
数据采集: 2023-04-03:chenxin01
最后编审: 2023-05-22:chenxin01
阅读次数: 31