SHIFTABLE MULTISCALE TRANSFORMS
SHIFTABLE MULTISCALE TRANSFORMS
复制标题
DOI：
10.1109/18.119725
复制
发表时间：
1992-03-01
影响因子：
2.5
通讯作者：
HEEGER, DJ
中科院分区：
文献类型：
--
作者：
SIMONCELLI, EP;FREEMAN, WT;HEEGER, DJ
正交小波变换最近已成为多尺度信号和图像分析的流行表示。这些表示的主要缺点之一是缺乏平移不变性：小波子带的内容在输入信号的平移下不稳定。小波变换对于输入信号的膨胀以及在二维中输入信号的旋转也是不稳定的。我们通过定义一种称为“可转移性”的平移不变性来形式化这些问题。在空间域中，可移位性对应于缺乏混叠；因此，该属性成立的条件由抽样定理指定。可移动性也可以在其他领域的背景下考虑，特别是方向和比例。探索了在多个域中同时可移动的“联合可移动”变换。设计并实现了联合可移位变换的两个示例：位置和尺度可联合移位的一维变换，以及位置和方向可联合移位的二维变换。演示了这些图像表示对于尺度空间分析、立体视差测量和图像增强的有用性。
Orthogonal wavelet transforms have recently become a popular representation for multiscale signal and image analysis. One of the major drawbacks of these representations is their lack of translation invariance: the content of wavelet subbands is unstable under translations of the input signal. Wavelet transforms are also unstable with respect to dilations of the input signal, and in two dimensions, rotations of the input signal. We formalize these problems by defining a type of translation invariance that we call "shiftability". In the spatial domain, shiftability corresponds to a lack of aliasing; thus, the conditions under which the property holds are specified by the sampling theorem. Shiftability may also be considered in the context of other domains, particularly orientation and scale. "Jointly shiftable" transforms that are simultaneously shiftable in more than one domain are explored. Two examples of jointly shiftable transforms are designed and implemented: a one-dimensional transform that is jointly shiftable in position and scale, and a two-dimensional transform that is jointly shiftable in position and orientation. The usefulness of these image representations for scale-space analysis, stereo disparity measurement, and image enhancement is demonstrated.