• Title/Summary/Keyword: Image Normalization

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A Comparison on the Image Normalizations for Image Information Estimation

  • Kang, Hwan-Il;Lim, Seung-Chul;Kim, Kab-Il;Son, Young-I
    • 제어로봇시스템학회:학술대회논문집
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    • 2005.06a
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    • pp.2385-2388
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    • 2005
  • In this paper, we propose the estimation method for the image affine information for computer vision. The first estimation method is given based on the XYS image normalization and the second estimation method is based on the image normalization by Pei and Lin. The XYS normalization method turns out to have better performance than the method by Pei and Lin. In addition, we show that rotation and aspect ratio information can be obtained using the central moments of both the original image and the sensed image. Finally, we propose the modified version of the normalization method so that we may control the size of the image.

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Affine-Invariant Image normalization for Log-Polar Images using Momentums

  • Son, Young-Ho;You, Bum-Jae;Oh, Sang-Rok;Park, Gwi-Tae
    • 제어로봇시스템학회:학술대회논문집
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    • 2003.10a
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    • pp.1140-1145
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    • 2003
  • Image normalization is one of the important areas in pattern recognition. Also, log-polar images are useful in the sense that their image data size is reduced dramatically comparing with conventional images and it is possible to develop faster pattern recognition algorithms. Especially, the log-polar image is very similar with the structure of human eyes. However, there are almost no researches on pattern recognition using the log-polar images while a number of researches on visual tracking have been executed. We propose an image normalization technique of log-polar images using momentums applicable for affine-invariant pattern recognition. We handle basic distortions of an image including translation, rotation, scaling, and skew of a log-polar image. The algorithm is experimented in a PC-based real-time vision system successfully.

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Design and Implementation of Binary Image Normalization Hardware for High Speed Processing (고속 처리를 위한 이진 영상 정규화 하드웨어의 설계 및 구현)

  • 김형구;강선미;김덕진
    • Journal of the Korean Institute of Telematics and Electronics B
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    • v.31B no.5
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    • pp.162-167
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    • 1994
  • The binary image normalization method in image processing can be used in several fields, Especially, its high speed processing method and its hardware implmentation is more useful, A normalization process of each character in character recognition requires a lot of processing time. Therefore, the research was done as a part of high speed process of OCR (optical character reader) implementation as a pipeline structure with host computer in hardware to give temporal parallism. For normalization process, general purpose CPU,MC68000, was used to implement it. As a result of experiment, the normalization speed of the hardware is sufficient to implement high speed OCR which the recognition speed is over 140 characters per second.

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An Improved Image Classification Using Batch Normalization and CNN (배치 정규화와 CNN을 이용한 개선된 영상분류 방법)

  • Ji, Myunggeun;Chun, Junchul;Kim, Namgi
    • Journal of Internet Computing and Services
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    • v.19 no.3
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    • pp.35-42
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    • 2018
  • Deep learning is known as a method of high accuracy among several methods for image classification. In this paper, we propose a method of enhancing the accuracy of image classification using CNN with a batch normalization method for classification of images using deep CNN (Convolutional Neural Network). In this paper, we propose a method to add a batch normalization layer to existing neural networks to enhance the accuracy of image classification. Batch normalization is a method to calculate and move the average and variance of each batch for reducing the deflection in each layer. In order to prove the superiority of the proposed method, Accuracy and mAP are measured by image classification experiments using five image data sets SHREC13, MNIST, SVHN, CIFAR-10, and CIFAR-100. Experimental results showed that the CNN with batch normalization is better classification accuracy and mAP rather than using the conventional CNN.

Image Watermarking Robust to Geometrical Attacks based on Normalization using Invariant Centroid (불변의 무게중심을 이용한 영상 정규화에 기반한 기하학적 공격에 강인한 워터마킹)

  • 김범수;최재각
    • Journal of KIISE:Information Networking
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    • v.31 no.3
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    • pp.243-251
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    • 2004
  • This paper proposes a digital image watermarking scheme, which is robust to geometrical attacks. The method improves image normalization-based watermarking (INW) technique that doesn't effectively deal with geometrical attacks with cropping. Image normalization is based on the moments of the image, however, in general, geometrical attacks bring the image boundary cropping and the moments are not preserved original ones. Thereafter the normalized images of before and after are not same form, i.e., the synchronization is lost. To solve the cropping problem of INW, Invariant Centroid (IC) is proposed in this paper. IC is a gravity center of a central area on a gray scale image that is invariant although an image is geometrically attacked and the only central area, which has less cropping possibility by geometrical attacks, is used for normalization. Experimental results show that the IC-based method is especially robust to geometrical attack with cropping.

A Robust Watermarking Technique Using Affine Transform and Cross-Reference Points (어파인 변형과 교차참조점을 이용한 강인한 워터마킹 기법)

  • Lee, Hang-Chan
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.56 no.3
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    • pp.615-622
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    • 2007
  • In general, Harris detector is commonly used for finding salient points in watermarking systems using feature points. Harris detector is a kind of combined comer and edge detector which is based on neighboring image data distribution, therefore it has some limitation to find accurate salient points after watermark embedding or any kinds of digital attacks. In this paper, we have used cross reference points which use not data distribution but geometrical structure of a normalized image in order to avoid pointing error caused by the distortion of image data. After normalization, we find cross reference points and take inverse normalization of these points. Next, we construct a group of triangles using tessellation with inversely normalized cross reference points. The watermarks are affine transformed and transformed-watermarks are embedded into not normalized image but original one. Only locations of watermarks are determined on the normalized image. Therefore, we can reduce data loss of watermark which is caused by inverse normalization. As a result, we can detect watermarks with high correlation after several digital attacks.

Local-Based Iterative Histogram Matching for Relative Radiometric Normalization

  • Seo, Dae Kyo;Eo, Yang Dam
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.37 no.5
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    • pp.323-330
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    • 2019
  • Radiometric normalization with multi-temporal satellite images is essential for time series analysis and change detection. Generally, relative radiometric normalization, which is an image-based method, is performed, and histogram matching is a representative method for normalizing the non-linear properties. However, since it utilizes global statistical information only, local information is not considered at all. Thus, this paper proposes a histogram matching method considering local information. The proposed method divides histograms based on density, mean, and standard deviation of image intensities, and performs histogram matching locally on the sub-histogram. The matched histogram is then further partitioned and this process is performed again, iteratively, controlled with the wasserstein distance. Finally, the proposed method is compared to global histogram matching. The experimental results show that the proposed method is visually and quantitatively superior to the conventional method, which indicates the applicability of the proposed method to the radiometric normalization of multi-temporal images with non-linear properties.

Analysis on Topographic Normalization Methods for 2019 Gangneung-East Sea Wildfire Area Using PlanetScope Imagery (2019 강릉-동해 산불 피해 지역에 대한 PlanetScope 영상을 이용한 지형 정규화 기법 분석)

  • Chung, Minkyung;Kim, Yongil
    • Korean Journal of Remote Sensing
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    • v.36 no.2_1
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    • pp.179-197
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    • 2020
  • Topographic normalization reduces the terrain effects on reflectance by adjusting the brightness values of the image pixels to be equal if the pixels cover the same land-cover. Topographic effects are induced by the imaging conditions and tend to be large in high mountainousregions. Therefore, image analysis on mountainous terrain such as estimation of wildfire damage assessment requires appropriate topographic normalization techniques to yield accurate image processing results. However, most of the previous studies focused on the evaluation of topographic normalization on satellite images with moderate-low spatial resolution. Thus, the alleviation of topographic effects on multi-temporal high-resolution images was not dealt enough. In this study, the evaluation of terrain normalization was performed for each band to select the optimal technical combinations for rapid and accurate wildfire damage assessment using PlanetScope images. PlanetScope has considerable potential in the disaster management field as it satisfies the rapid image acquisition by providing the 3 m resolution daily image with global coverage. For comparison of topographic normalization techniques, seven widely used methods were employed on both pre-fire and post-fire images. The analysis on bi-temporal images suggests the optimal combination of techniques which can be applied on images with different land-cover composition. Then, the vegetation index was calculated from the images after the topographic normalization with the proposed method. The wildfire damage detection results were obtained by thresholding the index and showed improvementsin detection accuracy for both object-based and pixel-based image analysis. In addition, the burn severity map was constructed to verify the effects oftopographic correction on a continuous distribution of brightness values.

The Bi-level Image Mapping Using Density Information in Character Patterns (문자패턴에서의 밀도정보를 이용한 이진영상 매핑)

  • 김봉석;강선미;양정윤;양윤모;김덕진
    • Journal of the Korean Institute of Telematics and Electronics B
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    • v.30B no.8
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    • pp.8-15
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    • 1993
  • This paper describes a normalization of character which is contained in the character recognition process. Line and dot density is computed on input character image and then image mapping is executed into destination. Also recognition is processed using overlap-partitioning of character image and extraction of 4 directional feature primitives. The validity of proposed nonlinear normalization algorithm could be verified by increment of recognition rate.

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