以全對焦影像合成技術修正失焦顯微鏡影像

Fully Focused Microscopic Image Based on Defocused Image segmentation and Integration Technology

林展緯(Zhan-Wei Lin)

指導教授 ： 林康平

中原大學/工學院/電機工程研究所/碩士(2005年)

https://doi.org/10.6840/cycu200500147

摘要

在光學照影中，景深問題往往困擾著使用者無法於一次拍攝中，得到一全對焦之清晰影像，而此現象發生於一般攝影以及顯微鏡照影上，在一般攝影中，可經由更換長景深鏡頭解決景深不足之問題，但在顯微鏡照影中，因放大倍率高，景深常為μm間距，故在觀測標本上，因景深過短之緣故，使得照影中只能得到一個斷層面之清晰影像，有鑑於此，本論文提出失焦重建演算法，基於有限景深之情況下，分割出各個失焦影像其清晰部分，並予以重建為一全對焦影像。
本論文改進失焦重建演方法需於同一場景之限制，經由「相關訊息影像對位演算法」，修正影像位移，校正影像位移所產生的誤差，並進行失焦重建之步驟，同時解決影像位移及失焦之情況，使此技術能以應用於更多不同之研究上。
本研究將以影像整體變異數驗證失焦重建結果與原始輸入失焦影像之差異，可明顯發現，其清晰度最大值皆為重建結果影像。並將此技術應用於各種顯微鏡影像上，重建失焦影像，以便後續應用與發展所需。

關鍵字

景深 ； 影像對位

並列摘要

In photographing, the depth of field has been an issue to the photographers. The depth of field often causes photographers unable to achieve a completely focused image through one single shot behavior. Such impossible behavior often occurs in regular and microscopic photographing processes. In regular photographing, the depth of field can be corrected using long depth of field lenses. However, due to the high magnification extent with a depth of field in micro meters (μm), so only one clear slice image can be obtained in each microscopic photographing process. In this paper presents the defocus reconstruction algorithm, as under the limited depth of field in microscopic photographing, to select each individual clear segments of the image to reconstruct them to one fully focused image.
The application of defocus reconstruction algorithm is always restricted to the same photographic scene process in the past. The algorithm is extending the new concept of using the “Mutual Information image registration” to correct the image displacement, for use in the similar image shift condition occurs as the result when specimen movement or stereo microscope is changing focus. The image registration corrects the image displacement error, and proceeds to the defocus reconstruction process to resolve the image displacement and defocused situation. This defocus reconstruction algorithm can be applied to other photographing areas.
This research adopts the image sharp value to evaluate the image reconstruction results. It is evident that the clearest images are all resulted from the depth of field reconstruction process. Therefore, this reconstruction algorithm is an effective method to apply in the microscopic photographing for image correction purposes.

並列關鍵字

depth of field ； image registration

參考文獻

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