1. Contrast Invariant SNR and Isotonic Regressions.
- Author
-
Weiss, Pierre, Escande, Paul, Bathie, Gabriel, and Dong, Yiqiu
- Subjects
- *
ISOTONIC regression , *COLOR image processing , *DIRECTED acyclic graphs , *IMAGE fusion , *IMAGE processing , *IMAGE registration - Abstract
We design an image quality measure independent of contrast changes, which are defined as a set of transformations preserving an order between the level lines of an image. This problem can be expressed as an isotonic regression problem. Depending on the definition of a level line, the partial order between adjacent regions can be defined through chains, polytrees or directed acyclic graphs. We provide a few analytic properties of the minimizers and design original optimization procedures together with a full complexity analysis. The methods worst case complexities range from O(n) for chains, to O (n log n) for polytrees and O (n 2 ϵ) for directed acyclic graphs, where n is the number of pixels and ϵ is a relative precision. The proposed algorithms have potential applications in change detection, stereo-vision, image registration, color image processing or image fusion. A C++ implementation with Matlab headers is available at https://github.com/pierre-weiss/contrast_invariant_snr. [ABSTRACT FROM AUTHOR]
- Published
- 2019
- Full Text
- View/download PDF