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Journal ArticleDOI

Multidirectional edge-directed interpolation with region division for natural images

01 Apr 2012-Optical Engineering (International Society for Optics and Photonics)-Vol. 51, Iss: 4, pp 040503-1-040503-3
TL;DR: A multidirectional edge-directed interpolation algo-rithm that features a region division method that shows that several directional edges are restored in a subjective test, with fair performance in an objec-tive test.
Abstract: Yujin Yun, Jonghyun Bae, and Jaeseok KimYonsei University, Department of Electrical and ElectronicEngineering, 50 Yonsei-ro, Seodaemun-gu, Seoul,Republic of KoreaE-mail: yujin.yun@yonsei.ac.krAbstract. A multidirectional edge-directed interpolation algo-rithm that features a region division method is proposed. Inthe proposed method, an interpolation pixel is newly modeledas a weighted sum of 12 neighboring pixels representing 12different directions. Each weight is estimated by Wiener filtertheory using geometric duality. The proposed method fordividing the interpolation region reduces the heavy computa-tional complexity of the proposed model. Analyzing edgecontinuities, the model divides an image into three regions,and only strong edge regions are interpolated. Simulationresults show that several directional edges are restoredclearly in a subjective test, with fair performance in an objec-tive test.
Citations
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Journal ArticleDOI
TL;DR: Zhang et al. as mentioned in this paper proposed a multidirectional weighted interpolation algorithm for color filter array interpolation, which exploits to greater degree correlations among neighboring pixels along eight directions to improve the interpolation performance.
Abstract: This paper presents a novel multidirectional weighted interpolation algorithm for color filter array interpolation. Our proposed method has two contributions to demosaicking. First, different from conventional interpolation methods based on two directions or four directions, the proposed method exploits to greater degree correlations among neighboring pixels along eight directions to improve the interpolation performance. Second, we propose an efficient postprocessing method to reduce interpolation artifacts based on the color difference planes. Compared with conventional state-of-the-art demosaicking algorithms, our experimental results show the proposed algorithm provides superior performance in both objective and subjective image quality. Furthermore, this implementation has moderate computational complexity.

43 citations

01 Jan 2015
TL;DR: This paper presents a novel multidirectional weighted interpolation algorithm for color filter array interpolation that exploits to greater degree correlations among neighboring pixels along eight directions to improve the interpolation performance.
Abstract: This paper presents a novel multidirectional weighted interpolation algorithm for color filter array inter- polation. Our proposed method has two contributions to demosaicking. First, different from conventional interpolation methods based on two directions or four directions, the proposed method exploits to greater degree correlations among neighboring pixels along eight directions to improve the interpolation perfor- mance. Second, we propose an efficient postprocessing method to reduce interpolation artifacts based on the color difference planes. Compared with conventional state-of-the-art demosaick- ing algorithms, our experimental results show the proposed algorithm provides superior performance in both objective and subjective image quality. Furthermore, this implementation has moderate computational complexity.

38 citations


Cites methods from "Multidirectional edge-directed inte..."

  • ...(a) Original #5 image from the McM image data set and the demosaicked images by, (b) DWI [7], (c) MEDI [35], (d) ESF [4], (e) SSD [8], (f) LPA-ICI [5], (g) LDI-NAT [6], (h) VDI [36], (i) MDWIN , and (j) MDWI....

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  • ...(a) Original #13 image from the McM image data set and the demosaicked images by, (b) DWI [7], (c) MEDI [35], (d) ESF [4], (e) SSD [8], (f) LPA-ICI [5], (g) LDI-NAT [6], (h) VDI [36], (i) MDWIN , and (j) MDWI....

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  • ...(a) Original #17 image from the McM image data set and the demosaicked images by, (b) DWI [7], (c) MEDI [35], (d) ESF [4], (e) SSD [8], (f) LPA-ICI [5], (g) LDI-NAT [6], (h) VDI [36], (i) MDWIN , and (j) MDWI....

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  • ...Although MEDI interpolates the missing color components along 12 directions, it had the second worst CPSNR performance of all the compared methods due to only the green color plane, which is exploited to estimate the center missing color component....

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  • ...Particularly, in MEDI [35], the missing color component is interpolated along 12 directions....

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Journal ArticleDOI
TL;DR: Simulation results verify that, the proposed framework performs better than state-of-the-art demosaicking methods in term of color peak signal-to-noise ratio (CPSNR) and feature similarity index measure (FSIM), as well as higher visual quality.
Abstract: In this letter, we proposed a new framework for color image demosaicking by using different strategies on green (G) and red/blue (R/B) components. Firstly, for G component, the missing samples are estimated by eight-direction weighted interpolation via exploiting spatial and spectral correlations of neighboring pixels. The G plane can be well reconstructed by considering the joint contribution of pre-estimations along eight interpolation directions with different weighting factors. Secondly, we estimate R/B components using guided filter with the reconstructed G plane as guidance image. Simulation results verify that, the proposed framework performs better than state-of-the-art demosaicking methods in term of color peak signal-to-noise ratio (CPSNR) and feature similarity index measure (FSIM), as well as higher visual quality.

36 citations


Additional excerpts

  • ...Finally, we reconstruct R plane by adding the residual to the pre-estimation....

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Journal ArticleDOI
TL;DR: Simulation results demonstrate that the proposed adaptive interpolation scheme can generate better visual quality of the magnified images with higher peak signal-to-noise ratio (PSNR), structural similarity (SSIM), feature similarity (FSIM) index, and reasonable execution time.
Abstract: Preserving edge structures and image details simultaneously is considered the main challenge for image interpolation techniques that produce high-resolution images from their low-resolution counterparts. Two variants of a new adaptive interpolation scheme are proposed in this paper. In the proposed scheme for better interpolation of natural images, a new estimation mechanism that utilizes discontinuities in blocks around missing pixels is devised to discriminate strong edges. Strong edge pixels are obtained by using amended error linear interpolation and cubic convolution interpolation. Adaptive interpolation weights determined by inverse intensity distances in local windows are used to produce non-strong edge pixels based on local image structure. The proposed amended linear interpolation and cubic convolution interpolation exhibited approximately comparable performances. Simulation results on different types of images, including natural, texture, and cartoon images, demonstrate that, compared with other state-of-the-art algorithms, the proposed algorithm can generate better visual quality of the magnified images with higher peak signal-to-noise ratio (PSNR), structural similarity (SSIM), feature similarity (FSIM) index, and reasonable execution time.

3 citations

Journal ArticleDOI
TL;DR: A new demosaicking method based on mixed color channel correlation based on geometric duality of Bayer CFA pattern and an efficiency promotion method by considering the local image texture complexity for real-time imaging system are proposed.
Abstract: In this paper, we proposed a new demosaicking method based on mixed color channel correlation. Different from conventional interpolation methods based on only two or four directions, the proposed method exploits the mixed color channel correlation within the local sliding window to improve the interpolation performance. The principle idea of our proposed method is based on the correlation of spatial closeness and spectral similarity between the high and low-resolution of the raw color filter array (CFA) image. By using geometric duality of Bayer CFA pattern, a robust interpolation model is proposed with optimal interpolation coefficients. We also proposed an efficiency promotion method by considering the local image texture complexity for real-time imaging system. As compared with the latest demosaicking algorithms, experiments show that the proposed algorithm provides superior performance in terms of both objective and subjective image qualities.

3 citations


Cites background or methods from "Multidirectional edge-directed inte..."

  • ...Finally, we compared CCAD with the conventional methods; DWI [7], MEDI [9], ESF [5] and LDI-NAT [8]....

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  • ...8 a Original #17 image from the McM image dataset and the demosaicked images b DWI [7]; c MEDI [9]; d ESF [5]; e LDI-NAT [8]; f CCAD-N and g CCAD Journal of Real-Time Image Processing (2019) 16:61–69 67...

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  • ...7 a Original #5 image from the McM image dataset and the demosaicked images by b DWI [7]; c MEDI [9]; d ESF [5]; e LDI-NAT [8]; f CCAD-N and g CCAD 66 Journal of Real-Time Image Processing (2019) 16:61–69...

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  • ...Particularly, in MEDI [9], the missing color & Young-Sup Lee ysl@incheon....

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References
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Journal ArticleDOI
TL;DR: In this article, a structural similarity index is proposed for image quality assessment based on the degradation of structural information, which can be applied to both subjective ratings and objective methods on a database of images compressed with JPEG and JPEG2000.
Abstract: Objective methods for assessing perceptual image quality traditionally attempted to quantify the visibility of errors (differences) between a distorted image and a reference image using a variety of known properties of the human visual system. Under the assumption that human visual perception is highly adapted for extracting structural information from a scene, we introduce an alternative complementary framework for quality assessment based on the degradation of structural information. As a specific example of this concept, we develop a structural similarity index and demonstrate its promise through a set of intuitive examples, as well as comparison to both subjective ratings and state-of-the-art objective methods on a database of images compressed with JPEG and JPEG2000. A MATLAB implementation of the proposed algorithm is available online at http://www.cns.nyu.edu//spl sim/lcv/ssim/.

40,609 citations

Journal ArticleDOI
TL;DR: Simulation results demonstrate that the new interpolation algorithm substantially improves the subjective quality of the interpolated images over conventional linear interpolation.
Abstract: This paper proposes an edge-directed interpolation algorithm for natural images. The basic idea is to first estimate local covariance coefficients from a low-resolution image and then use these covariance estimates to adapt the interpolation at a higher resolution based on the geometric duality between the low-resolution covariance and the high-resolution covariance. The edge-directed property of covariance-based adaptation attributes to its capability of tuning the interpolation coefficients to match an arbitrarily oriented step edge. A hybrid approach of switching between bilinear interpolation and covariance-based adaptive interpolation is proposed to reduce the overall computational complexity. Two important applications of the new interpolation algorithm are studied: resolution enhancement of grayscale images and reconstruction of color images from CCD samples. Simulation results demonstrate that our new interpolation algorithm substantially improves the subjective quality of the interpolated images over conventional linear interpolation.

1,933 citations


"Multidirectional edge-directed inte..." refers background or methods in this paper

  • ...NEDI restores high-quality images; however, it suffers from blocking artifacts because of the deficiency of edge directionality information and the geometric duality assumption.(1) While various modifications of NEDI in Refs....

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  • ...(3).(1) Y2i;2jþ1 and Y2iþ1;2j can be calculated in the same manner except that an interpolation window is slanted 45 deg....

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  • ...(1) is estimated by Wiener filter theory.(1) For the optimal minimum mean-square error (MMSE) condition, ~ α can be found as...

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Journal ArticleDOI
TL;DR: The author begins by discussing the image formation process and examines the demosaicking methods in three groups: the first group consists of heuristic approaches, the second group formulates demosaicked as a restoration problem, and the third group is a generalization that uses the spectral filtering model given in Wandell.
Abstract: The author begins by discussing the image formation process. The demosaicking methods are examined in three groups: the first group consists of heuristic approaches. The second group formulates demosaicking as a restoration problem. The third group is a generalization that uses the spectral filtering model given in Wandell.

616 citations

Proceedings Article
01 Jan 2008
TL;DR: The implementation of the new algorithm (iNEDI, improved New Edge Directed Interpolation), even if computationally heavy (as the Li and Orchard’s method), obtained quality scores that are notably higher than those obtained with NEDI and other methods presented in the literature.
Abstract: In this paper we analyse the problem of general purpose image upscaling that preserves edge features and natural appearance and we present the results of subjective and objective evaluation of images interpolated using different algorithms. In particular, we consider the well-known NEDI (New Edge Directed Interpolation, Li and Orchard, 2001) method, showing that by modifying it in order to reduce numerical instability and making the region used to estimate the low resolution covariance adaptive, it is possible to obtain relevant improvements in the interpolation quality. The implementation of the new algorithm (iNEDI, improved New Edge Directed Interpolation), even if computationally heavy (as the Li and Orchard’s method), obtained, in both subjective and objective tests, quality scores that are notably higher than those obtained with NEDI and other methods presented in the literature.

123 citations

Journal ArticleDOI
01 Aug 2009
TL;DR: Simulation results show that the proposed method achieves remarkable subjective performance in preserving the edge smoothness and sharpness among other methods in literature and demonstrates consistent objective performance among a variety of images.
Abstract: A modification of the new edge-directed interpolation method is presented. The modification eliminates the prediction error accumulation problem with adopting a modified training window structure, and further extends the covariance matching into multiple directions for suppressing the covariance mis-match problem. Simulation results show that the proposed method achieves remarkable subjective performance in preserving the edge smoothness and sharpness among other methods in literature. It also demonstrates consistent objective performance among a variety of images.

109 citations