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Quality Improvement of Interpolated Image Using Weight-Granting Method Based on Median Values Of Local Area

국부 영역 중앙값 기반의 가중치 부여 방법을 이용한 보간 영상의 화질 개선

  • 곽내정 (목원대학교 정보통신공학과) ;
  • 유성필 (충북대학교 전기전자공학부) ;
  • 안재형 (충북대학교 전기전자공학부) ;
  • 권동진 (충북대학교 전기전자공학부)
  • Published : 2007.12.28

Abstract

Interpolation methods to get the magnified image from an image with low resolution use known pixels to make an interpolated pixel. This interpolation process usually generates blurred edges and blocking effect in the result image. To improve these defects, conventional methods multiply proper weights reflecting neighborhood pixels and add the values during interpolating process. The proposed method changes input pixels in consideration of information of neighborhood pixels, gets interpolated pixels by using these values and improves the quality of interpolated image. Firstly, we compute difference values of the diagonal directions of a pixel and classify flat regions and complex regions according to these values. If the regions is complex ones, the proposed method changes an original pixel into a new value using a input pixel and a median value of it's neighbor pixels. Therefore, the proposed method applies bilinear method to the original pixels in flat regions and the changed ones in complex regions and produces the interpolated images. We evaluate the performance of the proposed method with existing methods by using PSNR and the quality of enlarged image. The results show that the proposed method improves PSNR in comparing with conventional methods and that is superior to the existing methods in terms of the quality of the interpolated image.

Keywords

Interpolation;Image Magnification;Bilinear Interpolation;Diagonal Direction