• 제목/요약/키워드: Histogram Binarization

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Lane detection method using Median Filter based Retinex Algorithm in Foggy Image (미디언 필터 기반의 Retinex 알고리즘을 통한 안개 영상에서의 차선검출 기법)

  • Kim, Young-Tak;Hahn, Hern-Soo
    • Journal of the Korea Society of Computer and Information
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    • v.15 no.8
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    • pp.31-39
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    • 2010
  • The paper proposes the median filter based Retinex algorithm to detect the lanes in a foggy image. Whether an input image is foggy or not is determined by analyzing the histogram in the pre-defined ROI(Region of Interest). If the image is determined as a foggy one, then it is improved by the median filter based Retinex algorithm. By replacing the Gaussian filter by the median filter in the Retinex algorithm, the processing time can be reduced and the lane features can be detected more robustly. Once the enhanced image is acquired, the binarization based on multi-threshold and the labeling operations are applied. Finally, it detects the lane information using the size and direction parameters of the detected lane features. The proposed algorithm has been evaluated by using various foggy images collected on different road conditions to prove that it detects lanes more robustly in most cases than the conventional methods.

Recognition Performance Improvement of QR and Color Codes Posted on Curved Surfaces (곡면상에 부착된 QR 코드와 칼라 코드의 인식률 개선)

  • Kim, Jin-soo
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.23 no.3
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    • pp.267-275
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    • 2019
  • Currently, due to the widespread use of a smartphone, QR codes allow users to access a variety of added services. However, the QR codes posted on curved surfaces tend to be non-uniformly illuminated and bring about the decline of recognition rate. So, in this paper, the block-adaptive binarization policy is adopted to find an optimal threshold appropriate for bimodal image like QR codes. For a large block, its histogram distribution is found to get an initial threshold and then the block is partitioned to reflect the local characteristics of small blocks. Also, morphological operation is applied to their neighboring boundary at the discontinuous at the QR code junction. This paper proposes an authentication method based on the color code, uniquely painted within QR code. Through a variety of practical experiments, it is shown that the proposed algorithm outperforms the conventional method in detecting QR code and also maintains good recognition rate up to 40 degrees on curved surfaces.