• Title/Summary/Keyword: Transformed image

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A Hierarchical Stereo Matching Algorithm Using Wavelet Representation (웨이브릿 변환을 이용한 계층적 스테레오 정합)

  • 김영석;이준재;하영호
    • Journal of the Korean Institute of Telematics and Electronics B
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    • v.31B no.8
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    • pp.74-86
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    • 1994
  • In this paper a hierarchical stereo matching algorithm to obtain the disparity in wavelet transformed domain by using locally adaptive window and weights is proposed. The pyramidal structure obtained by wavelet transform is used to solve the loss of information which the conventional Gaussian or Laplacian pyramid have. The wavelet transformed images are decomposed into the blurred image the horizontal edges the vertical edges and the diagonal edges. The similarity between each wavelet channel of left and right image determines the relative importance of each primitive and make the algorithm perform the area-based and feature-based matching adaptively. The wavelet transform can extract the features that have the dense resolution as well as can avoid the duplication or loss of information. Meanwhile the variable window that needs to obtain precise and stable estimation of correspondense is decided adaptively from the disparities estimated in coarse resolution and LL(low-low) channel of wavelet transformed stereo image. Also a new relaxation algorithm that can reduce the false match without the blurring of the disparity edge is proposed. The experimental results for various images show that the proposed algorithm has good perfpormance even if the images used in experiments have the unfavorable conditions.

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Pose Transformation of a Frontal Face Image by Invertible Meshwarp Algorithm (역전가능 메쉬워프 알고리즘에 의한 정면 얼굴 영상의 포즈 변형)

  • 오승택;전병환
    • Journal of KIISE:Software and Applications
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    • v.30 no.1_2
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    • pp.153-163
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    • 2003
  • In this paper, we propose a new technique of image based rendering(IBR) for the pose transformation of a face by using only a frontal face image and its mesh without a three-dimensional model. To substitute the 3D geometric model, first, we make up a standard mesh set of a certain person for several face sides ; front. left, right, half-left and half-right sides. For the given person, we compose only the frontal mesh of the frontal face image to be transformed. The other mesh is automatically generated based on the standard mesh set. And then, the frontal face image is geometrically transformed to give different view by using Invertible Meshwarp Algorithm, which is improved to tolerate the overlap or inversion of neighbor vertexes in the mesh. The same warping algorithm is used to generate the opening or closing effect of both eyes and a mouth. To evaluate the transformation performance, we capture dynamic images from 10 persons rotating their heads horizontally. And we measure the location error of 14 main features between the corresponding original and transformed facial images. That is, the average difference is calculated between the distances from the center of both eyes to each feature point for the corresponding original and transformed images. As a result, the average error in feature location is about 7.0% of the distance from the center of both eyes to the center of a mouth.

EFFICIENT IHS BASED IMAGE FUSION WITH 'COMPENSATIVE' MATRIX CONSTRUCTED BY SIMULATING THE SCALING PROCESS

  • Nguyen, TienCuong;Kim, Dae-Sung;Kim, Yong-Il
    • Proceedings of the KSRS Conference
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    • v.2
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    • pp.639-642
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    • 2006
  • The intensity-hue-saturation (IHS) technique has become a standard procedure in image analysis. It enhances the colour of highly correlated data. Unfortunately, IHS technique is sensitive to the properties of the analyzed area and usually faces colour distortion problems in the fused process. This paper explores the relationship of colour between before and after the fused process and the change in colour space of images. Subsequently, the fused colours are transformed back into the 'simulative' true colours by the following steps: (1) For each pixel of fused image that match with original pixel (of the coarse spectral resolution image) is transformed back to the true colour of original pixel. (2) The value for interpolating pixels is compensated to preserve the DN ratio between the original pixel and it's vicinity. The 'compensative matrix' is constructed by the DN of fused images and simulation of scaling process. An illustrative example of a Landsat and SPOT fused image also demonstrates the simulative true colour fusion methods.

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Bezier Control Points for the Image of a Domain Curve on a Bezier Surface (베지어 곡면의 도메인 곡선의 이미지 곡선에 대한 베지어 조정점의 계산)

  • 신하용
    • Korean Journal of Computational Design and Engineering
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    • v.1 no.2
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    • pp.158-162
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    • 1996
  • Algorithms to find the Bezier control points of the image of a Bezier domain curve on a Bezier surface are described. The diagonal image curve is analysed and the general linear case is transformed to the diagonal case. This proposed algorithm gives the closed form solution to find the control points of the image curve of a linear domain curve. If the domain curve is not linear, the image curve can be obtained by solving the system of linear equations.

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Image Processing in Digital 'Takbon' and the Decipherment of Epigraphic Letters (영상신호처리에 의한 디지털 탁본화 문자 판독)

  • 황재호
    • Proceedings of the IEEK Conference
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    • 2003.11a
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    • pp.27-30
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    • 2003
  • In this paper a new approach of digitalized ‘Takbon’ is introduced. By image signal processing, the letters which were written on stones can be deciphered. Epigraphic letter is detected by digital image device, digital camera. The two dimensional digital image is preprocessed because of sensor noise and detective turbulence. Color image is transformed into grey level. The letter image is analyzed in time/frequency domain. By the resultant analysis data decisive functions are calculated. Signal Processing techniques, such as scaling, clipping, digital negative, high/low filter, morphology and so on, provide algorithms that can extract letter from stones.

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Image Watermarking using Multiwavelet Transform and Color Characteristics of Human vision (인간 시각의 칼라특성과 다중 웨이블릿 변환을 이용한 워터마킹)

  • 전형섭;김정엽;현기호
    • Proceedings of the IEEK Conference
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    • 2002.06d
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    • pp.239-242
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    • 2002
  • The rapid expansion of the Internet in the past few years has rapidly increased the availability of digital data such as audio, images and videos to the public. Therefore, The need for copyright protect of digital data are increasing in the internet. In this paper, Color image(RGB model) is transformed into LUV model, it includes the characteristics of, human vision and then the U or V component is transformed into 3-level wavelet transform. we can insert watermark to several objects of an image separately The experimental results showed that the proposed watermarking algorithm was better than to other RGB watermarking algorithm.

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Quadtree image compression using isolated wavelet coefficients removal (고립점 제거를 이용한 웨이브릿 변환 영상의 트리구조 부호화)

  • 정현민;김용규;윤택현;김성만;박규태
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.21 no.7
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    • pp.1613-1623
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    • 1996
  • In this paper, an image coding scheme using removal of isolated coefficients and quadtree structure in wavelet transformed domain, is suggested. The number of significant coefficients can be reduced by quantizing in different stages according to the weights of the each band. The quadtree structure preseves the location information while significantly reducing the number of bits required to represent the locality of an image. To increase the efficienty of the wavelet transformed images using quadtree, the energy of the isolated coefficients is analyzed and those with low energy are eliminated. Furthermore, to control the bit rate the entropy of each block is sorted according to its energy concentration and the number of bits required for encoding, and the blocks with low energy are removed to achieve the desired compression rate.

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Robust pattern watermarking using wavelet transform and multi-weights (웨이브렛 변환과 다중 가중치를 이용한 강인한 패턴 워터마킹)

  • 김현환;김용민;김두영
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.25 no.3B
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    • pp.557-564
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    • 2000
  • This paper presents a watermarking algorithm for embedding visually recognizable pattern (Mark, Logo, Symbol, stamping or signature) into the image. first, the color image(RGB model)is transformed in YCbCr model and then the Y component is transformed into 3-level wavelet transform. Next, the values are assembled with pattern watermark. PN(pseudo noise) code at spread spectrum communication method and mutilevel watermark weights. This values are inserted into discrete wavelet domain. In our scheme, new calculating method is designed to calculate wavelet transform with integer value in considering the quantization error. and we used the color conversion with fixed-point arithmetic to be easy to make the hardware hereafter. Also, we made the new solution using mutilevel threshold to robust to common signal distortions and malicious attack, and to enhance quality of image in considering the human visual system. the experimental results showed that the proposed watermarking algorithm was superior to other similar water marking algorithm. We showed what it was robust to common signal processing and geometric transform such as brightness. contrast, filtering. scaling. JPEG lossy compression and geometric deformation.

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Generation of Color Sketch Images Using DIP Operator (DIP 연산자를 이용한 컬러 스케치 영상 생성)

  • So, Hyun-Joo;Jang, Ick-Hoon;Kim, Ji-Hong
    • Journal of Korea Multimedia Society
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    • v.12 no.7
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    • pp.947-952
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    • 2009
  • In this paper, we propose a method of generating color sketch images using the DIP operator. In the proposed method, an input RGB color image is first transformed into an HSV color image. A sketch image of the V component image is then extracted by applying the DIP operator to the V component image, which is the brightness component of the input image. For the visual convenience, the extracted sketch image of the V component image is next inverted and contrast-stretched. The S component image is also enhanced to deepen the color of output sketch image while maintaining its color. Finally, the V and S component images along with the original H component image are transformed into an output RGB color sketch image. Experimental results show that the proposed method yields output color sketch images similar to hand-drawn sketch pictures whose colors are the same as those of input color images.

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Image compression through projection of wavelet coefficients (웨이브릿 계수들이 투영을 이용한 영상압축 알고리즘)

  • 김철우;이승준;이충웅
    • Journal of the Korean Institute of Telematics and Electronics B
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    • v.33B no.9
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    • pp.80-87
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    • 1996
  • This paper proposes an image compression algorithm that adopts projection scheme on wavelet transform domain of image signal. Wavelet decomposed image is encoded by the result of projection along one direction out of eight which approximates the coefficients most closely to the originally transformed coefficients. These projectrion data are vector quantized using separate codebooks depending on the decomposition level and orientation of decomposed of image. Experimental results reveals that proposed scheme shows excellent performance in PSNR manner and also shows good subjective quality.

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