SlideShare a Scribd company logo
Sundarapandian et al. (Eds): CoNeCo,WiMo, NLP, CRYPSIS, ICAIT, ICDIP, ITCSE, CS & IT 07,
pp. 293–296, 2012. © CS & IT-CSCP 2012 DOI : 10.5121/csit.2012.2427
EXTENDED WAVELET TRANSFORM BASED
IMAGE INPAINTING ALGORITHM FOR
NATURAL SCENE IMAGE COMPLETION
K.Sangeetha1
, Dr.P.Sengottuvelan2
and E.Balamurugan3
1
Department of Computer Applications, BIT, Sathyamangalam, India
kavigeeth@gmail.com
2
Department of Information Technology, BIT, Sathyamangalam, India
psengottuvelan@rediffmail.com
3
Department of Computer Applications, BIT, Sathyamangalam, India
sanbala@rediffmail.com
ABSTRACT
This paper proposes an exemplar based image inpainting using extended wavelet transform. The
Image inpainting modifies an image with the available information outside the region to be
inpainted in an undetectable way. The extended wavelet transform is in two dimensions. The
Laplacian pyramid is first used to capture the point discontinuities, and then followed by a
directional filter bank to link point discontinuities into linear structures. The proposed model
effectively captures the edges and contours of natural scene images.
KEYWORDS
Extended Wavelet Transform, Exemplar Based, Image Inpainting
1. INTRODUCTION
The Image Inpainting is the art of modifying an image in a form that is not easily detectable by
an ordinary observer. The aim of algorithms evaluated in this paper is creating a visually pleasing
continuation of data around the hole in such a way that it is not detectable. In order to effectively
retain image data, various researchers have continually proposed various methods of image
inpainting and these works are classified into 2 major categories. One is non exemplar based
method and the other is exemplar based method.
Art repairers use their knowledge of the world and the abilities of the brain to complete missing
parts of something as the connectivity principle [2-3] and allow to "see" the missing parts of an
image and complete it in such way that one could think that nothing was ever missing. In our
model, uses the same approach with the least possible user interaction; only an inpainting area
must be informed by the user, meaning that the selection of the data that will fill the image is done
automatically.
2. RELATED WORK
In 2000 Bertalmio et al. [1] introduced the first aspects of digital inpainting, providing an
efficient way to routinely fill the target area. The technique gathers the information to complete
the inpainting region by applying a dispersal scheme based on partial differential equations
(PDEs) over the boundary of the area to be filled. The core of this method is to transmit
294 Computer Science & Information Technology ( CS & IT )
isophotes into the inpainting region, alternating with anisotropic diffusion for directional
smoothing. More recently, Tschumperl´e and Deriche [4] proposed a unified approach for image
restoration, object removal and resolution improvement also based on PDEs. In their paper, the
authors present a powerful mechanism for digital inpainting based on image regularization
through vector fields. Although both methods presented good results for relatively simple regions
they failed to complete larger texturized regions. The need to fill larger inpainting regions
provoked the development of techniques that propagate blocks of pixels per iteration instead of
isolated pixels.
The evolution of Bertalmio's work shown in [5] describes a mechanism that splits the image
information in texture and structure, supported by the methods devised in [5, 6]. The structured
part of the image is processed with an inpainting algorithm, and the texture is synthesized using
Efros' method [8]. Criminisi et al. [9] developed important work in digital inpainting with texture
synthesis. In their work, the authors state that exemplar-based texture synthesis suffices in order
to fill large inpainting regions. Criminisi's method estimates the gradient vector of the image and
a confidence term in order to determine the block that should be processed first at each iteration,
aiming to preserve both image structure and texture.
The wavelet transform has been widely used in the medical image processing [7]. The wavelet
transform is a type of multi-scale analysis that decomposes input signal into high frequency detail
and low frequency approximation components at various resolutions. To enhance features, the
selected detail wavelet coefficients are multiplied by an adaptive gain value. The image is then
enhanced by reconstructing the processed wavelet coefficients.
Do and Vetterli (10) utilized a double filter banks structure to develop the Contourlet transform
and used it for some nonlinear approximation and de-noising experiments and obtained some
hopeful results. In this work, a new approach for retinal image contrast enhancement that is
based on Contourlet transform is proposed. The main reason for the choice of Contourlet is
based on its better performance of representing edges and textures of natural images. The
proposed model achieves better visual results and outperformed the previous methods.
3. THE PROPOSED MODEL
3.1 Contourlet Transform
Contourlet Transform consists of two steps: the sub bands decomposition and the directional
transform. A Laplacian Pyramid is first used to capture point discontinuities, then followed by a
directional filter bank to link point discontinuity into linear structure. The overall result is an
image expansion using basic elements like contour segments.
Contourlet transform is well-adapted to represent images containing edges; it is a good candidate
for edge enhancement in natural images. Contourlet coefficients can be modified via a nonlinear
function ya. Taking noise into consideration, will introduce explicitly a noise standard deviation
σ in the equation.
if σ≤x<2ασ
if x≥t (1)
Computer Science & Information Technology ( CS & IT ) 295
Here, t determines the degree of nonlinearity and s introduces a dynamic range compression.
Using a nonzero s will enhance the faintest edges and soften the strongest edges. α is a
normalization parameter. The t parameter is the value under which coefficients are amplified. This value
depends obviously on the pixel values. It can derive the t value from the data.
4. RESULTS
We have experimented with the method [9] and our proposed model on some images comparing
with PSNR. These algorithms are programmed by matlab2008Ra and all experiments are run on
a 2.93GHz PC. The algorithm proposed by [9] succeeds in filling the target region without
implicit or explicit segmentation. The proposed model performs well as previous techniques
designed for the restoration of small scratches, and, in instances in which larger objects are
removed.
Figure 1 - 3 show the results produced by the aforementioned exemplar based Inpainting
algorithms. The images in each figure are arranged as original image, an image with occluded
region, the final result of methods in [9] and proposed model respectively.
Figure 1. Lady occluded region of image. (a) Original Image. (b)Mask image. (c) The output
image by Criminisi et al's algorithm [9]. (d) The output image by the proposed model.
(a) (b) (c) (d)
Figure 2. Man occluded region of image. (a) Original Image. (b)Mask image. (c) The output image
by Criminisi et al's algorithm [9]. (d) The output image by the proposed model
(a) (b) (c) (d)
Figure 3. Bird occluded region of image. (a) Original Image. (b)Mask image. (c) The output image
by Criminisi et al's algorithm [9]. (d) The output image by the proposed model
296 Computer Science & Information Technology ( CS & IT )
(a) (b) (c) (d)
Table 1 PSNR value for the two exemplar based image inpainting Results
Image
Lady occluded
image
Man occluded
image
Bird occluded
imageMethod
Criminisi et al's 33.12 33.16 33.22
Proposed model 36.29 35.89 36.53
5. CONCLUSIONS
With the exemplar- based texture synthesis, the proposed image restoration method can restore
structure features and composite textures both for large and thick or long and thin blackened
regions without blurring. As evidenced by the experiments with the Contourlet transform, there
is better preservation of contours than with other methods. The Contourlet can detect the
contours and edges quite adequately. We have planned to work on methods to restore complex
structures such as corners, curves etc.
REFERENCES
[1] Bertalmio, M., Sapiro, G., Caselles, V., Ballester, C.: Image inpainting. In: Proceedings of
SIGGRAPH 2000, pp. 417-424. ACM Press, New York (2000)
[2] Kokaram, A., Morris, R., Fitzgerald, W.,Rayner, P.: Interpolation of missing data in image sequences.
IEEE Trans. Image Processing 11, 1509-1519 (1995)
[3] Pessoa, L., Thompson, E., Noe, A.: Finding out about filling-in: A guide to perceptual completion for
visual science and the philosophy of perception. Behavioral and Brain Sciences 21(6), 723-
748(1998)
[4] Tschumperle, D., Deriche, R.: Vector-valued image regularization with PDEs: A common framework
for different applications. IEEE Trans. Pattern Anal. Mach. Intell. 27(4), 506- 517 (2005).
[5] Bertalmio, M., Vese, L., Sapiro, G., Osher, S.: Simultaneous structure and texture image inpainting
IEEE Trans. Image Processing 12, 882-889 (2003). Meyer, Y.: Oscillating Patterns in Image
Processing and Nonlinear Evolution Equations. American Mathematical Society, Boston (2001).
[6] Vese, L.A., Osher, S.J.: Modeling textures with total variation minimization and oscillating patterns
in image processing. J. Sci. Comput. 19(1-3), 553-572 (2003).
[7] Fu, J.C., Chai, J.W., Wong, S.T.C., 2000a. Wavelet-based enhancement for detection of left
ventricular myocardial boundaries in magnetic resonance images. Magn. Reson. Imaging 18 (9),
1135-1141.
[8] Efros, A.A., Leung, T.K.: Texture synthesis by non-parametric sampling. In: IEEE International
Conference on Computer Vision, pp. 1033-1038. Corfu, Greece (1999).
[9] Criminisi, A., Perez, P., Toyama, K.: Region filling and object removal by exemplar based image
inpainting. IEEE Trans. Image Processing 13(9), 1200-1212 (2004)

More Related Content

PDF
44 paper
PDF
Spectral approach to image projection with cubic b spline interpolation
PDF
A STUDY AND ANALYSIS OF DIFFERENT EDGE DETECTION TECHNIQUES
PDF
G1802053147
PDF
Image compression using sand algorithm
PDF
H1802054851
PDF
An approach to improving edge
PDF
N42018588
44 paper
Spectral approach to image projection with cubic b spline interpolation
A STUDY AND ANALYSIS OF DIFFERENT EDGE DETECTION TECHNIQUES
G1802053147
Image compression using sand algorithm
H1802054851
An approach to improving edge
N42018588

What's hot (18)

PDF
Study of Image Inpainting Technique Based on TV Model
PPTX
A study and comparison of different image segmentation algorithms
PDF
By4301435440
PDF
A comparison between scilab inbuilt module and novel method for image fusion
PDF
REGION CLASSIFICATION BASED IMAGE DENOISING USING SHEARLET AND WAVELET TRANSF...
PPTX
Comparison of Segmentation Algorithms and Estimation of Optimal Segmentation ...
PDF
Medial axis transformation based skeletonzation of image patterns using image...
PPT
Image mosaicing
PDF
Performance of Efficient Closed-Form Solution to Comprehensive Frontier Exposure
PDF
Object based image enhancement
PDF
A Survey on Exemplar-Based Image Inpainting Techniques
PDF
A novel approach for efficient skull stripping using
PDF
Interpolation Technique using Non Linear Partial Differential Equation with E...
PDF
A CONCERT EVALUATION OF EXEMPLAR BASED IMAGE INPAINTING ALGORITHMS FOR NATURA...
PDF
A Combined Model for Image Inpainting
PDF
Performance analysis on color image mosaicing techniques on FPGA
PDF
A novel approach for efficient skull stripping using morphological reconstruc...
PDF
A MODIFIED HISTOGRAM BASED FAST ENHANCEMENT ALGORITHM
Study of Image Inpainting Technique Based on TV Model
A study and comparison of different image segmentation algorithms
By4301435440
A comparison between scilab inbuilt module and novel method for image fusion
REGION CLASSIFICATION BASED IMAGE DENOISING USING SHEARLET AND WAVELET TRANSF...
Comparison of Segmentation Algorithms and Estimation of Optimal Segmentation ...
Medial axis transformation based skeletonzation of image patterns using image...
Image mosaicing
Performance of Efficient Closed-Form Solution to Comprehensive Frontier Exposure
Object based image enhancement
A Survey on Exemplar-Based Image Inpainting Techniques
A novel approach for efficient skull stripping using
Interpolation Technique using Non Linear Partial Differential Equation with E...
A CONCERT EVALUATION OF EXEMPLAR BASED IMAGE INPAINTING ALGORITHMS FOR NATURA...
A Combined Model for Image Inpainting
Performance analysis on color image mosaicing techniques on FPGA
A novel approach for efficient skull stripping using morphological reconstruc...
A MODIFIED HISTOGRAM BASED FAST ENHANCEMENT ALGORITHM
Ad

Similar to EXTENDED WAVELET TRANSFORM BASED IMAGE INPAINTING ALGORITHM FOR NATURAL SCENE IMAGE COMPLETION (20)

PDF
Comparative Study and Analysis of Image Inpainting Techniques
PDF
A Review on Deformation Measurement from Speckle Patterns using Digital Image...
PDF
REMOVING OCCLUSION IN IMAGES USING SPARSE PROCESSING AND TEXTURE SYNTHESIS
PDF
A NOVEL APPROACH TO SMOOTHING ON 3D STRUCTURED ADAPTIVE MESH OF THE KINECT-BA...
PDF
Spectral approach to image projection with cubic
PDF
Gr3511821184
PDF
H010315356
PDF
APPLICATION OF IMAGE FUSION FOR ENHANCING THE QUALITY OF AN IMAGE
PDF
G04654247
PDF
A Novel Undistorted Image Fusion and DWT Based Compression Model with FPGA Im...
PDF
One dimensional vector based pattern
PDF
A NOVEL APPROACH TO SMOOTHING ON 3D STRUCTURED ADAPTIVE MESH OF THE KINECT-BA...
PDF
IRJET- Multi Image Morphing: A Review
PDF
Object Shape Representation by Kernel Density Feature Points Estimator
PDF
A MODIFIED HISTOGRAM BASED FAST ENHANCEMENT ALGORITHM
PDF
A Review on Image Compression using DCT and DWT
PDF
Development and Comparison of Image Fusion Techniques for CT&MRI Images
PDF
Structure tensor-based Gaussian kernel edge-adaptive depth map refinement wit...
PDF
Wavelet-Based Warping Technique for Mobile Devices
PDF
INFORMATION SATURATION IN MULTISPECTRAL PIXEL LEVEL IMAGE FUSION
Comparative Study and Analysis of Image Inpainting Techniques
A Review on Deformation Measurement from Speckle Patterns using Digital Image...
REMOVING OCCLUSION IN IMAGES USING SPARSE PROCESSING AND TEXTURE SYNTHESIS
A NOVEL APPROACH TO SMOOTHING ON 3D STRUCTURED ADAPTIVE MESH OF THE KINECT-BA...
Spectral approach to image projection with cubic
Gr3511821184
H010315356
APPLICATION OF IMAGE FUSION FOR ENHANCING THE QUALITY OF AN IMAGE
G04654247
A Novel Undistorted Image Fusion and DWT Based Compression Model with FPGA Im...
One dimensional vector based pattern
A NOVEL APPROACH TO SMOOTHING ON 3D STRUCTURED ADAPTIVE MESH OF THE KINECT-BA...
IRJET- Multi Image Morphing: A Review
Object Shape Representation by Kernel Density Feature Points Estimator
A MODIFIED HISTOGRAM BASED FAST ENHANCEMENT ALGORITHM
A Review on Image Compression using DCT and DWT
Development and Comparison of Image Fusion Techniques for CT&MRI Images
Structure tensor-based Gaussian kernel edge-adaptive depth map refinement wit...
Wavelet-Based Warping Technique for Mobile Devices
INFORMATION SATURATION IN MULTISPECTRAL PIXEL LEVEL IMAGE FUSION
Ad

More from cscpconf (20)

PDF
ANALYSIS OF LAND SURFACE DEFORMATION GRADIENT BY DINSAR
PDF
4D AUTOMATIC LIP-READING FOR SPEAKER'S FACE IDENTIFCATION
PDF
MOVING FROM WATERFALL TO AGILE PROCESS IN SOFTWARE ENGINEERING CAPSTONE PROJE...
PDF
PROMOTING STUDENT ENGAGEMENT USING SOCIAL MEDIA TECHNOLOGIES
PDF
A SURVEY ON QUESTION ANSWERING SYSTEMS: THE ADVANCES OF FUZZY LOGIC
PDF
DYNAMIC PHONE WARPING – A METHOD TO MEASURE THE DISTANCE BETWEEN PRONUNCIATIONS
PDF
INTELLIGENT ELECTRONIC ASSESSMENT FOR SUBJECTIVE EXAMS
PDF
TWO DISCRETE BINARY VERSIONS OF AFRICAN BUFFALO OPTIMIZATION METAHEURISTIC
PDF
DETECTION OF ALGORITHMICALLY GENERATED MALICIOUS DOMAIN
PDF
GLOBAL MUSIC ASSET ASSURANCE DIGITAL CURRENCY: A DRM SOLUTION FOR STREAMING C...
PDF
IMPORTANCE OF VERB SUFFIX MAPPING IN DISCOURSE TRANSLATION SYSTEM
PDF
EXACT SOLUTIONS OF A FAMILY OF HIGHER-DIMENSIONAL SPACE-TIME FRACTIONAL KDV-T...
PDF
AUTOMATED PENETRATION TESTING: AN OVERVIEW
PDF
CLASSIFICATION OF ALZHEIMER USING fMRI DATA AND BRAIN NETWORK
PDF
VALIDATION METHOD OF FUZZY ASSOCIATION RULES BASED ON FUZZY FORMAL CONCEPT AN...
PDF
PROBABILITY BASED CLUSTER EXPANSION OVERSAMPLING TECHNIQUE FOR IMBALANCED DATA
PDF
CHARACTER AND IMAGE RECOGNITION FOR DATA CATALOGING IN ECOLOGICAL RESEARCH
PDF
SOCIAL MEDIA ANALYTICS FOR SENTIMENT ANALYSIS AND EVENT DETECTION IN SMART CI...
PDF
SOCIAL NETWORK HATE SPEECH DETECTION FOR AMHARIC LANGUAGE
PDF
GENERAL REGRESSION NEURAL NETWORK BASED POS TAGGING FOR NEPALI TEXT
ANALYSIS OF LAND SURFACE DEFORMATION GRADIENT BY DINSAR
4D AUTOMATIC LIP-READING FOR SPEAKER'S FACE IDENTIFCATION
MOVING FROM WATERFALL TO AGILE PROCESS IN SOFTWARE ENGINEERING CAPSTONE PROJE...
PROMOTING STUDENT ENGAGEMENT USING SOCIAL MEDIA TECHNOLOGIES
A SURVEY ON QUESTION ANSWERING SYSTEMS: THE ADVANCES OF FUZZY LOGIC
DYNAMIC PHONE WARPING – A METHOD TO MEASURE THE DISTANCE BETWEEN PRONUNCIATIONS
INTELLIGENT ELECTRONIC ASSESSMENT FOR SUBJECTIVE EXAMS
TWO DISCRETE BINARY VERSIONS OF AFRICAN BUFFALO OPTIMIZATION METAHEURISTIC
DETECTION OF ALGORITHMICALLY GENERATED MALICIOUS DOMAIN
GLOBAL MUSIC ASSET ASSURANCE DIGITAL CURRENCY: A DRM SOLUTION FOR STREAMING C...
IMPORTANCE OF VERB SUFFIX MAPPING IN DISCOURSE TRANSLATION SYSTEM
EXACT SOLUTIONS OF A FAMILY OF HIGHER-DIMENSIONAL SPACE-TIME FRACTIONAL KDV-T...
AUTOMATED PENETRATION TESTING: AN OVERVIEW
CLASSIFICATION OF ALZHEIMER USING fMRI DATA AND BRAIN NETWORK
VALIDATION METHOD OF FUZZY ASSOCIATION RULES BASED ON FUZZY FORMAL CONCEPT AN...
PROBABILITY BASED CLUSTER EXPANSION OVERSAMPLING TECHNIQUE FOR IMBALANCED DATA
CHARACTER AND IMAGE RECOGNITION FOR DATA CATALOGING IN ECOLOGICAL RESEARCH
SOCIAL MEDIA ANALYTICS FOR SENTIMENT ANALYSIS AND EVENT DETECTION IN SMART CI...
SOCIAL NETWORK HATE SPEECH DETECTION FOR AMHARIC LANGUAGE
GENERAL REGRESSION NEURAL NETWORK BASED POS TAGGING FOR NEPALI TEXT

Recently uploaded (20)

PDF
STATICS OF THE RIGID BODIES Hibbelers.pdf
PPTX
Lesson notes of climatology university.
PDF
Microbial disease of the cardiovascular and lymphatic systems
PPTX
PPT- ENG7_QUARTER1_LESSON1_WEEK1. IMAGERY -DESCRIPTIONS pptx.pptx
PDF
3rd Neelam Sanjeevareddy Memorial Lecture.pdf
PDF
Black Hat USA 2025 - Micro ICS Summit - ICS/OT Threat Landscape
PDF
Insiders guide to clinical Medicine.pdf
PDF
O7-L3 Supply Chain Operations - ICLT Program
PDF
Anesthesia in Laparoscopic Surgery in India
PPTX
Renaissance Architecture: A Journey from Faith to Humanism
PDF
VCE English Exam - Section C Student Revision Booklet
PPTX
GDM (1) (1).pptx small presentation for students
PPTX
1st Inaugural Professorial Lecture held on 19th February 2020 (Governance and...
PDF
Complications of Minimal Access Surgery at WLH
PPTX
Pharma ospi slides which help in ospi learning
PPTX
Cell Types and Its function , kingdom of life
PPTX
IMMUNITY IMMUNITY refers to protection against infection, and the immune syst...
PDF
01-Introduction-to-Information-Management.pdf
PPTX
master seminar digital applications in india
PDF
Physiotherapy_for_Respiratory_and_Cardiac_Problems WEBBER.pdf
STATICS OF THE RIGID BODIES Hibbelers.pdf
Lesson notes of climatology university.
Microbial disease of the cardiovascular and lymphatic systems
PPT- ENG7_QUARTER1_LESSON1_WEEK1. IMAGERY -DESCRIPTIONS pptx.pptx
3rd Neelam Sanjeevareddy Memorial Lecture.pdf
Black Hat USA 2025 - Micro ICS Summit - ICS/OT Threat Landscape
Insiders guide to clinical Medicine.pdf
O7-L3 Supply Chain Operations - ICLT Program
Anesthesia in Laparoscopic Surgery in India
Renaissance Architecture: A Journey from Faith to Humanism
VCE English Exam - Section C Student Revision Booklet
GDM (1) (1).pptx small presentation for students
1st Inaugural Professorial Lecture held on 19th February 2020 (Governance and...
Complications of Minimal Access Surgery at WLH
Pharma ospi slides which help in ospi learning
Cell Types and Its function , kingdom of life
IMMUNITY IMMUNITY refers to protection against infection, and the immune syst...
01-Introduction-to-Information-Management.pdf
master seminar digital applications in india
Physiotherapy_for_Respiratory_and_Cardiac_Problems WEBBER.pdf

EXTENDED WAVELET TRANSFORM BASED IMAGE INPAINTING ALGORITHM FOR NATURAL SCENE IMAGE COMPLETION

  • 1. Sundarapandian et al. (Eds): CoNeCo,WiMo, NLP, CRYPSIS, ICAIT, ICDIP, ITCSE, CS & IT 07, pp. 293–296, 2012. © CS & IT-CSCP 2012 DOI : 10.5121/csit.2012.2427 EXTENDED WAVELET TRANSFORM BASED IMAGE INPAINTING ALGORITHM FOR NATURAL SCENE IMAGE COMPLETION K.Sangeetha1 , Dr.P.Sengottuvelan2 and E.Balamurugan3 1 Department of Computer Applications, BIT, Sathyamangalam, India [email protected] 2 Department of Information Technology, BIT, Sathyamangalam, India [email protected] 3 Department of Computer Applications, BIT, Sathyamangalam, India [email protected] ABSTRACT This paper proposes an exemplar based image inpainting using extended wavelet transform. The Image inpainting modifies an image with the available information outside the region to be inpainted in an undetectable way. The extended wavelet transform is in two dimensions. The Laplacian pyramid is first used to capture the point discontinuities, and then followed by a directional filter bank to link point discontinuities into linear structures. The proposed model effectively captures the edges and contours of natural scene images. KEYWORDS Extended Wavelet Transform, Exemplar Based, Image Inpainting 1. INTRODUCTION The Image Inpainting is the art of modifying an image in a form that is not easily detectable by an ordinary observer. The aim of algorithms evaluated in this paper is creating a visually pleasing continuation of data around the hole in such a way that it is not detectable. In order to effectively retain image data, various researchers have continually proposed various methods of image inpainting and these works are classified into 2 major categories. One is non exemplar based method and the other is exemplar based method. Art repairers use their knowledge of the world and the abilities of the brain to complete missing parts of something as the connectivity principle [2-3] and allow to "see" the missing parts of an image and complete it in such way that one could think that nothing was ever missing. In our model, uses the same approach with the least possible user interaction; only an inpainting area must be informed by the user, meaning that the selection of the data that will fill the image is done automatically. 2. RELATED WORK In 2000 Bertalmio et al. [1] introduced the first aspects of digital inpainting, providing an efficient way to routinely fill the target area. The technique gathers the information to complete the inpainting region by applying a dispersal scheme based on partial differential equations (PDEs) over the boundary of the area to be filled. The core of this method is to transmit
  • 2. 294 Computer Science & Information Technology ( CS & IT ) isophotes into the inpainting region, alternating with anisotropic diffusion for directional smoothing. More recently, Tschumperl´e and Deriche [4] proposed a unified approach for image restoration, object removal and resolution improvement also based on PDEs. In their paper, the authors present a powerful mechanism for digital inpainting based on image regularization through vector fields. Although both methods presented good results for relatively simple regions they failed to complete larger texturized regions. The need to fill larger inpainting regions provoked the development of techniques that propagate blocks of pixels per iteration instead of isolated pixels. The evolution of Bertalmio's work shown in [5] describes a mechanism that splits the image information in texture and structure, supported by the methods devised in [5, 6]. The structured part of the image is processed with an inpainting algorithm, and the texture is synthesized using Efros' method [8]. Criminisi et al. [9] developed important work in digital inpainting with texture synthesis. In their work, the authors state that exemplar-based texture synthesis suffices in order to fill large inpainting regions. Criminisi's method estimates the gradient vector of the image and a confidence term in order to determine the block that should be processed first at each iteration, aiming to preserve both image structure and texture. The wavelet transform has been widely used in the medical image processing [7]. The wavelet transform is a type of multi-scale analysis that decomposes input signal into high frequency detail and low frequency approximation components at various resolutions. To enhance features, the selected detail wavelet coefficients are multiplied by an adaptive gain value. The image is then enhanced by reconstructing the processed wavelet coefficients. Do and Vetterli (10) utilized a double filter banks structure to develop the Contourlet transform and used it for some nonlinear approximation and de-noising experiments and obtained some hopeful results. In this work, a new approach for retinal image contrast enhancement that is based on Contourlet transform is proposed. The main reason for the choice of Contourlet is based on its better performance of representing edges and textures of natural images. The proposed model achieves better visual results and outperformed the previous methods. 3. THE PROPOSED MODEL 3.1 Contourlet Transform Contourlet Transform consists of two steps: the sub bands decomposition and the directional transform. A Laplacian Pyramid is first used to capture point discontinuities, then followed by a directional filter bank to link point discontinuity into linear structure. The overall result is an image expansion using basic elements like contour segments. Contourlet transform is well-adapted to represent images containing edges; it is a good candidate for edge enhancement in natural images. Contourlet coefficients can be modified via a nonlinear function ya. Taking noise into consideration, will introduce explicitly a noise standard deviation σ in the equation. if σ≤x<2ασ if x≥t (1)
  • 3. Computer Science & Information Technology ( CS & IT ) 295 Here, t determines the degree of nonlinearity and s introduces a dynamic range compression. Using a nonzero s will enhance the faintest edges and soften the strongest edges. α is a normalization parameter. The t parameter is the value under which coefficients are amplified. This value depends obviously on the pixel values. It can derive the t value from the data. 4. RESULTS We have experimented with the method [9] and our proposed model on some images comparing with PSNR. These algorithms are programmed by matlab2008Ra and all experiments are run on a 2.93GHz PC. The algorithm proposed by [9] succeeds in filling the target region without implicit or explicit segmentation. The proposed model performs well as previous techniques designed for the restoration of small scratches, and, in instances in which larger objects are removed. Figure 1 - 3 show the results produced by the aforementioned exemplar based Inpainting algorithms. The images in each figure are arranged as original image, an image with occluded region, the final result of methods in [9] and proposed model respectively. Figure 1. Lady occluded region of image. (a) Original Image. (b)Mask image. (c) The output image by Criminisi et al's algorithm [9]. (d) The output image by the proposed model. (a) (b) (c) (d) Figure 2. Man occluded region of image. (a) Original Image. (b)Mask image. (c) The output image by Criminisi et al's algorithm [9]. (d) The output image by the proposed model (a) (b) (c) (d) Figure 3. Bird occluded region of image. (a) Original Image. (b)Mask image. (c) The output image by Criminisi et al's algorithm [9]. (d) The output image by the proposed model
  • 4. 296 Computer Science & Information Technology ( CS & IT ) (a) (b) (c) (d) Table 1 PSNR value for the two exemplar based image inpainting Results Image Lady occluded image Man occluded image Bird occluded imageMethod Criminisi et al's 33.12 33.16 33.22 Proposed model 36.29 35.89 36.53 5. CONCLUSIONS With the exemplar- based texture synthesis, the proposed image restoration method can restore structure features and composite textures both for large and thick or long and thin blackened regions without blurring. As evidenced by the experiments with the Contourlet transform, there is better preservation of contours than with other methods. The Contourlet can detect the contours and edges quite adequately. We have planned to work on methods to restore complex structures such as corners, curves etc. REFERENCES [1] Bertalmio, M., Sapiro, G., Caselles, V., Ballester, C.: Image inpainting. In: Proceedings of SIGGRAPH 2000, pp. 417-424. ACM Press, New York (2000) [2] Kokaram, A., Morris, R., Fitzgerald, W.,Rayner, P.: Interpolation of missing data in image sequences. IEEE Trans. Image Processing 11, 1509-1519 (1995) [3] Pessoa, L., Thompson, E., Noe, A.: Finding out about filling-in: A guide to perceptual completion for visual science and the philosophy of perception. Behavioral and Brain Sciences 21(6), 723- 748(1998) [4] Tschumperle, D., Deriche, R.: Vector-valued image regularization with PDEs: A common framework for different applications. IEEE Trans. Pattern Anal. Mach. Intell. 27(4), 506- 517 (2005). [5] Bertalmio, M., Vese, L., Sapiro, G., Osher, S.: Simultaneous structure and texture image inpainting IEEE Trans. Image Processing 12, 882-889 (2003). Meyer, Y.: Oscillating Patterns in Image Processing and Nonlinear Evolution Equations. American Mathematical Society, Boston (2001). [6] Vese, L.A., Osher, S.J.: Modeling textures with total variation minimization and oscillating patterns in image processing. J. Sci. Comput. 19(1-3), 553-572 (2003). [7] Fu, J.C., Chai, J.W., Wong, S.T.C., 2000a. Wavelet-based enhancement for detection of left ventricular myocardial boundaries in magnetic resonance images. Magn. Reson. Imaging 18 (9), 1135-1141. [8] Efros, A.A., Leung, T.K.: Texture synthesis by non-parametric sampling. In: IEEE International Conference on Computer Vision, pp. 1033-1038. Corfu, Greece (1999). [9] Criminisi, A., Perez, P., Toyama, K.: Region filling and object removal by exemplar based image inpainting. IEEE Trans. Image Processing 13(9), 1200-1212 (2004)