计算机工程
計算機工程
계산궤공정
COMPUTER ENGINEERING
2015年
2期
224-227,233
,共5页
图像插值%线性插值%Tyler展开式%邻域滤波%自适应方法%双边滤波
圖像插值%線性插值%Tyler展開式%鄰域濾波%自適應方法%雙邊濾波
도상삽치%선성삽치%Tyler전개식%린역려파%자괄응방법%쌍변려파
image interpolation%linear interpolation%Tyler expansion%neighborhood filtering%adaptive method%bilateral filtering
图像待插像素用其邻域内连续方向上像素的Tyler展开可以得到较好的近似，但是沿着灰度连续和不连续方向(跨越图像边缘方向)的Tyler展开近似的线性平均会增加图像边缘宽度，引起图像边缘的视觉模糊以及产生锯齿边缘。为此，通过一个与灰度距离相关的权函数，自适应选择待插像素邻域内的Tyler展开，提出一个邻域滤波图像插值方法。与待插像素位于图像边缘同侧的像素权函数的值较大，像素的Tyler展开被选择为待插像素的近似；反之则权函数的值较小，像素的Tyler展开不用作待插像素的Tyler展开。实验结果表明，该方法避免了跨越图像边缘的Tyler展开的线性平均，可减小插值图像边缘的宽度，增加边缘斜坡坡度，从而获得清晰的插值图像边缘。
圖像待插像素用其鄰域內連續方嚮上像素的Tyler展開可以得到較好的近似，但是沿著灰度連續和不連續方嚮(跨越圖像邊緣方嚮)的Tyler展開近似的線性平均會增加圖像邊緣寬度，引起圖像邊緣的視覺模糊以及產生鋸齒邊緣。為此，通過一箇與灰度距離相關的權函數，自適應選擇待插像素鄰域內的Tyler展開，提齣一箇鄰域濾波圖像插值方法。與待插像素位于圖像邊緣同側的像素權函數的值較大，像素的Tyler展開被選擇為待插像素的近似；反之則權函數的值較小，像素的Tyler展開不用作待插像素的Tyler展開。實驗結果錶明，該方法避免瞭跨越圖像邊緣的Tyler展開的線性平均，可減小插值圖像邊緣的寬度，增加邊緣斜坡坡度，從而穫得清晰的插值圖像邊緣。
도상대삽상소용기린역내련속방향상상소적Tyler전개가이득도교호적근사，단시연착회도련속화불련속방향(과월도상변연방향)적Tyler전개근사적선성평균회증가도상변연관도，인기도상변연적시각모호이급산생거치변연。위차，통과일개여회도거리상관적권함수，자괄응선택대삽상소린역내적Tyler전개，제출일개린역려파도상삽치방법。여대삽상소위우도상변연동측적상소권함수적치교대，상소적Tyler전개피선택위대삽상소적근사；반지칙권함수적치교소，상소적Tyler전개불용작대삽상소적Tyler전개。실험결과표명，해방법피면료과월도상변연적Tyler전개적선성평균，가감소삽치도상변연적관도，증가변연사파파도，종이획득청석적삽치도상변연。
The interpolated pixel can be expanded along the direction on which image grey is continuously varied by Tyler expansion. But the linear average of these Tyler expansions along the continuous and discontinuous direction will enlarge the width of image edges and introduce blurring and zigzag effects. In this paper, a neighborhood filtering for image interpolation is proposed. A weighted function based on grey distance adaptively selects the Tyler expansions in the neighborhood of interpolated pixel. The principle of the method is that the weight of the pixel which lies on the same lateral of image edges with the interpolated pixel is large,so its Tyler expansion is selected,vice versa,the weight is small and its Tyler expansion is not selected. It avoids the average of the expansions which cross the image edges, and can reduce width of edge and increase slope,which produce scrip edges.
