基於視覺反應之快速影像縮小與放大

人類視覺在影像處理扮演重要關鍵。然而，依據幾何光學，我們發現眼睛並不是一個完美的光學系統，它的清晰區域非常小。所以，設計完美的影像產生系統，如果超出眼睛所能感知的能力，將會造成浪費。基於此一結果，我們提出3個應用領域。第1，「尖銳區域著色法」，用於加速3D場景之產生。第2，「多重解析度影像壓縮法」，可以提高影像壓縮率。第3，「快速影像縮放法」。雖然此法所縮放過的影像產生鋸齒狀，然而其速度比其它方法快達22到40倍，因此相當適合用於虛擬實境，光學字元、符號與車牌辨識。此一演算法沒有用到浮點數運算，所以也相當適合應用於嵌入式系統，如個人數位助理。

關鍵字

人類視覺系統；視覺尖銳區域；影像縮放；多項式片段趨近法；像點複製；隨機像點複製；羅森編碼

並列摘要

Human Visual System plays an important factor in image processing. However, based on geometric optics, we found the eye is not a perfect optical system; its “Region of Sharp Area” is very small. Therefore, it would be wasteful to design a system with perfect image render of which the eye could not utilize. Based on this result, we introduce three kinds of applications. First, we investigated a “Region Of Sharp Area” render, with this scheme, we have successfully speeded up the 3D scenes generation. Secondly, we proposed a “Multiple Resolution Image Compression” algorithm, with this method, we have successfully improved the image compression ratio. Thirdly, we develop a fast image resizing scheme that produces significantly improved quality over the pixel replication method. This algorithm is suitable for real-time image resizing applications including: Virtual Reality, Optical Character Recognition, Symbol Recognition, and Car License Plate Recognition. Although this method produced “jaggies” at the edges in the resized image, the execution time is about 22 to 40 times fast than the Windows and the Weiman scheme, respectively. This scheme doesn't use floating-point operations and buffer area, so, it is suitable for image viewer based on embedded system, such as Portable Digital Assistant.

並列關鍵字

Human Visual System ； Region Of Sharp Area ； Image Resize ； Piecewise Polynomial Approximation ； Pixel Replication ； Random Pixel Replication ； Rothstein code

參考文獻

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[7] C. F. R. Weiman, “Continuous Anti-Aliased Rotation and Zoom of Raster Images,” SIGGRAPH ’80 Proc., vol. 14, pp. 286–293, July 1980.

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基於視覺反應之快速影像縮小與放大

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