Abstract

This paper presents a novel structure-preserving image decomposition operator called bilateral texture filter. As a simple modification of the original bilateral filter [Tomasi and Manduchi 1998], it performs local patch-based analysis of texture features and incorporates its results into the range filter kernel. The central idea to ensure proper texture/structure separation is based on patch shift that captures the texture information from the most representative texture patch clear of prominent structure edges. Our method outperforms the original bilateral filter in removing texture while preserving main image structures, at the cost of some added computation. It inherits well-known advantages of the bilateral filter, such as simplicity, local nature, ease of implementation, scalability, and adaptability to other application scenarios.

1 Introduction

Structure-preserving filtering is an essential operation with a variety of applications in computational photography and image analysis. Such an operation decomposes an image into prominent structure and fine-scale detail, making it easier for subsequent image manipulation such as tone mapping, detail enhancement, visual abstraction, scene understanding, and other tasks. Separating structure from detail often depends on measuring the size of local contrast, where structure is identified as pixels having relatively large contrast. However, when the fine-scale detail represents texture, as in Fig. 1, the conventional way of image decomposition may fail because texture often contains strong enough contrast to get confused with structure.

7 Discussion and Future Work

Our bilateral texture filter retains the simplicity of the original bilateral filter, yet provides significantly enhanced performance in separating texture details from image structures. We expect this simplicity, efficiency, and effectiveness to open up interesting application possibilities. The proposed patch shift mechanism plays a key role in our method as it finds appropriate texture/smooth patch for each pixel that is needed to generate a guidance image. Patch shift is a general concept and does not depend on any specific definition of texture feature. Therefore, its usefulness and applicability could be further explored in a larger context of research on image processing.