237
2014 Fourth International Conference on Emerging Applications of Information Technology
An Adaptive Bilateral Filter For Inpainting
A Dao Nam Anh
Department of Information Technology
Electric Power University
235 Hoang Quoc Viet road, Hanoi, Vietnam
Fig. 1. Example of inpainting: a) Input image, b) Mask and full/partial Gaussian filter, c) Inpainting result
Abstract— An adaptive model of bilateral filter is presented
for digital inpainting. The model works by transforming
inpainting into an equivalent energy condition minimization and
generation of patches for missing areas by interpolating within
working frame. It combines knowledge of local structure by
bilateral filter and intensive value. Bilateral filter is adapted to
missing regions to check similarity of regions to fill-in. Standard
deviation in range kernel of the filter is regulated by total
variation. This helps to create patches that keep edges. Total
variation is also efficient for detection of missing pixels which
possibly stay on edges. Benefit of the model was demonstrated in
experiment of inpainting for gray and color images.
Keywords— Inpainting, total variation, bilateral filter,
similarity, edge-preserving filter
I. INTRODUCTION
Image inpainting play a fundamental role in improvement
for unity and completeness of image. It is still open research
topic in image analysis. Typical algorithm would take missing
areas and use information of good areas to restore the missing
areas.
The conventional methods for solving this problem use
Partial Differential Equations (PDE) in iterative algorithms.
Pixels of missing area in the border with good areas are
checked with their neighbor pixels in good area by PDE based
functions. This runs in each iterative cycle until all missing
pixels were recovered.
Exemplar based methods, similar to PDE approach, also
run around the border of missing area, but they check each
small region of pixels but not a single pixel. Exemplars with
specific structure are created by small regions in known area
and they are used like example to fill-in missing area.
Bilateral filter introduced firstly into image denoising
application. This non-linear filter uses Gaussian in the spatial
domain where weight of each pixel is influenced by the
intensity domain. Its advantage is to eliminate noise but keep
edges. This paper work follows concept of the exemplar based
methods, incorporating with total variation (TV) and bilateral
filter to check similarity of structure. In adopting bilateral filter
concept, incomplete bilateral filter was introduced in optimal
condition, presenting similarity of intensive value and structure
between missing and good areas of image.
II. OUTLINE OF PAPER
Related work contributions and notation for this work are
presented in section 2, 3, 4, 5. In section 6, major concept of
adaptive bilateral filter for inpainting is formulated. The
section explains how bilateral filter can be transformed into
suitable form for checking similarity regions in image. Section
6 presents the experimental evaluation of the total variation
bilateral filter for inpainting gray and color images.
Before describing paper work in details, let’s see figure 1
for visual display of working concept. Fig.1a shows input
image. Fig.1b draws full Gaussian net in left and partial net in
right. The partial net is an example of incomplete bilateral filter
for a pixel on border of paint mask, that produces result in
fig.1c.
III. PREVIOUS AND RELATED WORK
Image inpainting has practical application and several
researches addressed to the topic. PDE based algorithm is
proposed by Marcelo Bertalmio et al [1]. PDE based methods
found success in iterative algorithms. Pixels of missing area in
the border with good area are checked with their neighbor
pixels in good area by PDE based functions. This is run in each
iterative cycle until all missing pixels were recovered.
Exemplar based methods, similar to PDE, also run around
the border of missing area. It checks each small region of
pixels but not a single pixel. Exemplars with specific structure
978-1-4799-4272-5/14 $31.00 © 2014 IEEE
DOI 10.1109/EAT.2014.13