影像增強功能是影像處理中非常重要的基本處理技術,透過適當的影像增強處理技術可以將原本模糊不清,甚至根本無法分辨的原始圖片,處理成更為清晰可用的圖像。因此,該類影像增強技術不論在醫學、遙控感知、微生物、刑事偵查以及軍事發展等領域上,均能得到廣泛的應用且效果顯著;然而,對圖像進行即時增強的困難度相當高。在此,我們利用FPGA硬體實現的方式,從空間域的角度對圖像的灰度直方圖進行均衡增強,提高其可看度與識別度。 在本論文中,先由CMOS 影像感測器獲取連續影像畫面,接著把每一張圖像轉換為RGB三原色,將RGB的數值轉換成灰階數值,再經過直方圖等化演算法轉換統計求取其亮度值的均勻分佈,達到即時動態影像畫面中亮度調整的效果。最後,我們以FPGA硬體來驗證本論文所提出的「利用灰度直方圖演算法來實現即時影像增強功能」方法,證明其能夠改善畫面亮度品質。
Image enhancement is an important processing technology in image processing, especially for image brightness enhancement. The Histogram equalization algorithm not only enhance the brightness of image, but also improves the resolution of image.This algorithm is widely used in medical image enhancement, remote sensing, microbial, and military development.However, the real-time image enhancement is hard to be implemented. In this paper, FPGA is used to implement the gray-level histogram equalization not only to enhance the visibility but also to increase the image recognization. In this study, the CMOS image sensor is used to capture the images continuously.Those images will be converted into RGB values which are converted to grayscale values by histogram equalization algorithm. After averaging those RGB values, one can adjust brightness of image screen immediately.Finally, FPGA hardware is used to verify the proposed method in this study.The destination is to improve the quality of screen brightness.