- 學位論文
一個基於影像處理技術的空氣手槍靶紙自動計分系統
An Automatic Scoring System for Air Pistol Shooting Competition Based on Image Processing Techniques
摘要
傳統空氣槍競賽計分方式以人力作業為主，此計分方式有處理時間過長且耗損人力過多，效率低安全性差等問題。雖已發明自動偵測靶紙彈孔分數及計分系統，但必須從國外進口價格相當昂貴，故打靶自動計分系統的研究，有助提升射擊運動的普及性。 本研究探討如何利用影像處理自動計算靶紙分數與辨識靶紙序號。自動計算靶紙分數主要分為彈孔提取以及計算彈孔與靶紙中心之距離。在彈孔提取部分，本論文利用彩色RGB資訊，偵測特定顏色，分割出彈孔；接著使用霍夫圓偵測找出彈孔之圓心，再由彈孔中心到靶心的距離計算出分數。序號辨識則是分為三個部份，即定位、分割與辨識；定位方法為序號可能會出現的四個位置，利用黑色像素個數判斷其所在位置，使用輪廓偵測分割出字元，最後利用模板比對，辨識出結果；本實驗共有50個樣本，判斷50個序號與300個字元。數字辨識成功率高達99.3%，序號辨識成功率也有96%。在重疊彈孔的情況下，使用霍夫圓依然可以偵測到彈孔，但是如果邊緣變的破碎會造成辨識的困難，另外重疊率超過75%之後，兩個彈孔過於靠近，將會只辨識成一個。
並列摘要
Traditionally, the shooting scores for air pistol competition are processed manually. These come with a lot of issues such as the lengthy processing time, great demand on manpower and even security concern. Currently, automatic score recording technology has been developed, but the resulting products must be imported and they are usually expensive. For the sake of gaining popularity of shooting sports, developing an automatic score recording system becomes a meaningful research work. This study investigates how to apply image processing techniques to automatically determine the score and recognize the series number on a target sheet. The score is determined in two major steps, namely extracting a bullet hole and calculating the distance between the bullet hole and the center of the target sheet. In bullet hole extraction, this work uses RGB color information to detect a specific color and identify the bullet hole. Then the center of the bullet hole is found by using the Hough circle detection method. The distance between the bullet hole center and the center of the target sheet is used to calculate the score. The serial number recognition tasks are divided into three parts, namely, positioning, segmentation and identification. Positioning means to find the exact location of the series numbers at the four possible places according to the numbers of black pixels counted. Contour detection is used to segment the number characters and the characters are recognized based on template matching. A total of 50 target sheet samples are tested in this experiment, which means we have 50 serial numbers and 300 characters under test. The 99.3% success rate is achieved on character recognition and the success rate for serial number identification is 96%. In the case of overlapping holes, using the Hough circle detection method can still detect a bullet hole. However, if the hole edges are broken and uneven, the detection becomes difficult when the holes are overlapped more than 75%. In this case, the two bullet holes are too close and they will be treated as just one single hole.