Novel Bayesian deringing method in image interpolation and compression using a SGLI prior

Jung, Cheolkon,Jiao, Licheng The Optical Society 2010 Optics express Vol.18 No.7

<P>This paper provides a novel Bayesian deringing method to reduce ringing artifacts caused by image interpolation and JPEG compression. To remove the ringing artifacts, the proposed method uses a Bayesian framework based on a SGLI (spatial-gradient-local-inhomogeneity) prior. The SGLI prior employs two complementary discontinuity measures: spatial gradient and local inhomogeniety. The spatial gradient measure effectively detects strong edge components in images. In addition, the local inhomogeniety measure successfully detects locations of the significant discontinuities by taking uniformity of small regions into consideration. The two complementary measures are elaborately combined to create prior probabilities of the Bayesian deringing framework. Thus, the proposed deringing method can effectively preserve the significant discontinuities such as textures of objects as well as the strong edge components in images while reducing the ringing artifacts. Experimental results show that the proposed deringing method achieves average PSNR gains of 0.09 dB in image interpolation artifact reduction and 0.21 dB in JPEG compression artifact reduction.</P>

Accurate text localization in images based on SVM output scores

Jung, Cheolkon,Liu, Qifeng,Kim, Joongkyu Elsevier 2009 Image and vision computing Vol.27 No.9

<P><B>Abstract</B></P><P>In this paper, we propose a new approach for accurate text localization in images based on SVM (support vector machine) output scores. In general, SVM output scores for the verification of text candidates provide a measure of the closeness to the text. Up to the present, most researchers used the score for verifying the text candidate region whether it is text or not. However, we use the output score for refining the initial localized text lines and selecting the best localization result from the different pyramid levels. By means of the proposed approach, we can obtain more accurate text localization results. Our method has three modules: (1) text candidate detection based on edge-CCA (connected component analysis), (2) text candidate verification based on the classifier fusion of N-gray (normalized gray intensity) and CGV (constant gradient variance), and (3) text line refinement based on the SVM output score, color distribution and prior geometric knowledge. By means of experiments on a large news database, we demonstrate that our method achieves impressive performance with respect to the accuracy, robustness and efficiency.</P>

Intensity-guided edge-preserving depth upsampling through weighted L₀ gradient minimization

Jung, Cheolkon,Yu, Shengtao,Kim, Joongkyu Elsevier 2017 Journal of visual communication and image represen Vol.42 No.-

<P><B>Abstract</B></P> <P>Depth is an important visual cue to perceive real-world scenes. Although a time-of-flight (ToF) depth camera can provide depth information in dynamic scenes, captured depth images are often noisy and of low resolution. In this paper, we propose an intensity-guided edge-preserving depth upsampling method through weighted L<SUB>0</SUB> gradient minimization to enhance both resolution and visual quality of depth images. Guided by the high-resolution intensity image, we perform optimization to preserve boundaries of objects. We apply L<SUB>0</SUB> gradient to the regularization term, and compute its weight from both intensity and depth images. We optimize the objective function using alternating minimization and half-quadratic splitting. Experimental results on Middlebury 2005, 2014, and real-world scene datasets demonstrate that the proposed method produces boundary-preserving depth upsampling results and outperforms state-of-the-art ones in terms of accuracy.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Intensity-guided edge-preserving depth upsampling. </LI> <LI> Weighted L<SUB>0</SUB> gradient minimization. </LI> <LI> Alternating minimization and half-quadratic splitting. </LI> <LI> Suppressing edge blurring and texture copying artifacts. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

A Novel Approach for Key Caption Detection in Golf Videos Using Color Patterns

Cheolkon Jung,Joongkyu Kim 한국전자통신연구원 2008 ETRI Journal Vol.30 No.5

This paper provides a novel method of detecting key captions containing player information in golf videos. We use the color pattern of captions and its repetition property to determine the key captions. The experimental results show that the proposed method achieves a much higher accuracy than existing methods.

Automatic Superimposed Text Localization from Video Using Temporal Information

Cheolkon Jung(정철곤),Joongkyu Kim(김중규) 한국통신학회 2007 韓國通信學會論文誌 Vol.32 No.9

Player Information Extraction for Semantic Annotation in Golf Videos

Cheolkon Jung,Joongkyu Kim IEEE 2009 IEEE transactions on broadcasting Vol.55 No.1

<P>In sports videos, text provides semantic information about the game such as scores and players. This paper provides an accurate extraction method of the player information in golf. First, a new detection method of the key captions containing the player information is presented. Since the location of the key captions containing the player information is not fixed during a game in golf, we use a color pattern of captions and its temporal repetition property instead of the location property to decide the key captions. Second, a dual binarization method is presented to segment texts with different color polarities (i.e. dark and bright texts) easily from the background in the key captions. Finally, the binarization results are recognized by OCR and converted to plain texts. The player is recognized by comparing the plain texts with the pre-reserved player name database. Experiments on a large database show that our method can extract the player information efficiently in golf videos.</P>

마코프 랜덤 필드를 이용한 움직이는 객체의 자동분할

정철곤(Cheolkon Jung),김중규(Joongkyu Kim) 한국통신학회 2001 한국통신학회 학술대회논문집 Vol.2001 No.11

골프 동영상에서의 강건한 선수명 인식

정철곤(Cheolkon Jung),김중규(Joongkyu Kim) 한국HCI학회 2008 한국HCI학회 학술대회 Vol.2008 No.2

스포츠의 경기에서 비디오 문자는 득점이나 선수명과 같은 중요한 정보를 제공한다. 본 논문에서는 골프 동영상에서 선수명 정보를 강건하게 인식하는 방법을 제안한다. 골프 경기의 경우, 원하는 선수의 플레이 장면을 검색하고자 하는 요구가 많은 스포츠 종목이다. 이러한 기능을 구현하기 위해 골프 동영상에 포함된 문자 정보를 이용한다. OCR 에 의해 검출된 문자 정보를 인식한 후, 사전 등록된 선수명 DB 를 이용해 선수명 정보를 인식한다. 이렇게 획득된 선수명 정보를 이용해 원하는 선수의 플레이 장면을 검색할 수 있도록 하였다. 다양한 골프 동영상에 대하여 실험을 수행한 결과, 본 논문에서 제안한 방법이 강건하게 선수명을 인식하는 것을 확인하였다. In sports videos, text provides valuable information about the game such as scores and information about the players. This paper proposed a robust recognition method of player name in golf videos. In golf, most of users want to search the scenes which contain the play shots of favorite players. We use text information in golf videos for robust extraction of player information, By using OCR, we have obtained the text information, and then recognized the player information from player name DB. We can search the scenes of favorite players by using this player information. By conducting experiments on several golf videos, we demonstrate that our method achieves impressive performance with respect to the robustness.

스트록 필터를 이용한 문자영역 이진화에 관한 연구

정철곤(Cheolkon Jung),김중규(Joongkyu Kim) 한국통신학회 2008 韓國通信學會論文誌 Vol.33 No.2c

비디오 문자는 중요한 내용정보를 담고 있기 때문에 비디오의 내용 해석에 있어서 매우 중요한 정보이다. 본 논문에서는 스트록 필터를 이용해 자동으로 문자영역을 이진화하는 방법을 제안하였다. 제안된 문자 이진화 방법은 스트록 필터에 의한 문자컬러극성 결정단계, 스트록 필터의 응답치에 대한 이진화 단계, 그리고 국소 영역 확장 단계로 구성되어 있다. 본 방법은 스트록 필터의 응답치를 이용해 문자의 컬러 극성을 결정함으로 인해 극성결정 성능이 뛰어나다. 또한 문자의 획 특성을 고려해 문자영역을 이진화하기 때문에 배경영역의 변화에 대하여 강인한 이진화 성능을 나타낸다. 다양한 비디오 영상에 대하여 실험한 결과, 이진화 성능이 우수함을 확인할 수 있었다. The videotext brings important semantic clues into video content analysis. In this paper, we propose an automatic binarization method of text region using a stroke filter. Proposed text binarization method consists of stroke filtering, text color polarity determination, and local region growing. By using the responses of dark and bright stroke filters, we can determine color polarity of text region automatically. And the method is robust against complex background, because it considers stroke information of videotexts by using a stroke filter. The effectiveness of our method is verified by experiments on a challenging database.

스코어 정보를 이용한 농구 비디오의 자동요약

정철곤(Cheolkon Jung),김의진(Eui-Jin Kim),이광국(Gwang-Gook Lee),김회율(Whoi-Yul Kim) 한국통신학회 2007 韓國通信學會論文誌 Vol.32 No.9