物件特徵分析於自動化切割與分類之研究及其在醫學影像之病變偵測的應用

A Study of Object-oriented Features Analysis for Automatic Image Segmentation and Classification and It’s Applications to Medical Images for Disease Detection

曹雅婷(Ya-Ting Tsao)

指導教授 ： 吳憲珠

國立臺中科技大學/資訊學群/資訊工程系碩士班/碩士(2011年)

https://doi.org/10.6826/NUTC.2011.00064

摘要

在本論文中，主要探討自動化切割與分類應用於醫學影像之研究。一般在臨床上，醫學影像造影與判讀皆需要人工介入進行處理，需耗費許多醫療人力資源同時也增加醫師的疲勞度。因此藉由電腦快速的運算能力以便自動的切割出血球影像中各種類型血球的位置和大小，以期能由電腦自動判讀出正確的血球影像而不需人工的介入。而自動判讀的依據往往是根據觀察血球的面積、形狀的變化、或是有任何病變的特徵，因此需擷取出最具影響力之特徵，使其達到有效的切割與分類之效果。
首先，本論文在第三章提出一個自動化的切割方法找出溶血性貧血中紅血球病變的部份進行。其切割方法為先去除背景和雜訊，之後將單一顆的紅血球進行邊緣變化的分析找出病變。而重疊的紅血球利用鏈碼技術找出高凹點的位置，其凹點的資訊再運用circle-fit演算法將重疊的血球分別分割出來。本技術能有效的找出病變的血球數量。
在第四章中，本論文又進一步的提出可將不同的溶血性貧血形態進行分類的方法。利用八方向的鏈碼演算法(chain code)找出邊緣的變化與方向，而後再做特徵的擷取將鏈碼做差值運算及鏈碼依序方向的變化。則再將擷取出來的特徵利用分類器進行訓練測試，從實驗結果顯示，本技術能有效的達到溶血性貧血類型之辨識。
第五章提出一個在巨紅血球貧血中計算出細胞核葉片數的自動化切割。首先將細胞核利用色彩空間切割出來，再運用距離轉化技術(distance transform)找出物件中心位置，在此同時利用圓擴張的方式將細胞核的葉片分別分離出來。本技術能將不規則的細胞核切割並計算出來，並分辨出其病徵與嗜中性白血球的不同之處。

關鍵字

醫學影像切割與分類 ； 血球影像 ； 溶血性貧血 ； 巨紅血球貧血

並列摘要

In this thesis we mainly discuss the application of automatic image segmentation and classification in the research of medical image. Clinically, medical imaging and interpretation requires human works, costing abundant of medical human resource and increasing the loading of staffs. Therefore, the thesis seeks for an automatic way to identify the images correctly via the vast computing ability of computers to automatically cut and categorize the location and size of various types of the blood cells from the smear image without human efforts. Automatic identification is based on observing the area, shape varieties and other features of disease of the blood cells. Thus, it is essential to extract the most significant feature to effectively categorize the cells.
First, an automatic image segmentation scheme to filter the Hemolytic Anemia blood cells from the healthy ones is proposed in Chapter 3. The proposed method first removes the background and noises in the blood images and then each single erythrocyte is analyzed by using the changes in the edges. For segmenting the overlapping erythrocytes, the edge directions of the cells are acquired by using chain code technique to find out the points of high concavity that can be adapted to circle-fit algorithm to separate each erythrocyte. The proposed scheme could effectively analyze the numbers of normal erythrocytes and poikilocytes according to the experimental results.
In Chapter 4, this thesis proposes an automatic method for segmentation and classification of erythrocytes from the patients with Hemolytic Anemia. By applying 8-connection chain code, the direction of edges change can be analyzed. Then extract the variation of eight directions from the individual erythrocyte as feature for classifying four main Hemolytic Anemia types. From the experimental results, the proposed method can calculate the quantity of erythrocytes and recognize the type of Hemolytic Anemia effectively.
Chapter 5 presents an automatic segmentation method for calculating blood cell of nucleus with Megaloblastic Anemia. First, use RGB color space to segment the nuclei from the blood image. Then utilize distance transform to figure out the center points information which is then adapted to expansion of circle to separate each nucleus from the object in the image. The proposed method will eventually analyze the numbers of nucleus in the blood smears. The proposed scheme can segment and calculate irregular clustered nuclei. Therefore, the number of nucleus can determine whether the multisegmented neutrophils are Megaloblastosic Anemia or not.

並列關鍵字

medical image segmentation and classification ； blood image ； Hemolytic Anemia ； Megaloblastosic Anemia

參考文獻

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