PowerShellで動画の輪郭検出をしてみる

OpenCVSharpを使用してWebカメラから動画をキャプチャーしながら輪郭検出をしてみる。
静止画と同じではつまらないので、円の中の４点を赤色にして、その４点の座標を緑の字でウィンドウ上に表示させてみる。

1. [void][System.Reflection.Assembly]::LoadFrom((Join-Path $pwd OpenCvSharp.dll))
3. $camera = [OpenCvSharp.CvCapture]::FromCamera(0)
4. $window = New-Object OpenCvSharp.CvWindow("SampleCapture")
6. $threshold = 128 #　白色か黒色かのしきい値
7. $smooth = 5 #　値が大きいほどぼかしが強い
9. $font = New-Object OpenCvSharp.CvFont([OpenCvSharp.FontFace]::HersheyComplex, 0.7, 0.7)
10. $point1 = New-Object OpenCvSharp.CvPoint(10,20)
11. $point25 = New-Object OpenCvSharp.CvPoint(10,45)
12. $point50 = New-Object OpenCvSharp.CvPoint(10,70)
13. $point75 = New-Object OpenCvSharp.CvPoint(10,95)
15. $colorString = [OpenCvSharp.CvColor]::Green
16. $colorPoint = [OpenCvSharp.CvColor]::Red
17. $colorLine = [OpenCvSharp.CvColor]::Blue
19. $size = New-Object OpenCvSharp.CvSize(15, 15)
20. #　この値が大きいほど輪郭が狭まる
21. $tremCriteria = New-Object OpenCvSharp.CvTermCriteria(300)
23. $alpha = [System.Single]0.45
24. $beta = [System.Single]0.35
25. $gamma = [System.Single]0.2
27. $srcSize = New-Object OpenCvSharp.CvSize($camera.FrameWidth, $camera.FrameHeight)
28. $srcIplImage = New-Object OpenCvSharp.IplImage( $srcSize, [OpenCvSharp.BitDepth]::U8, 1)
29. $dstIplImage = New-Object OpenCvSharp.IplImage( $srcSize, [OpenCvSharp.BitDepth]::U8, 1)
31. #　ポイントを配列で初期化　全部ゼロで初期化される
32. [OpenCvSharp.CvPoint[]]$contour = New-Object OpenCvSharp.CvPoint[](100)
34. #　ウィンドウの中心点を取得
35. $center = New-Object OpenCvSharp.CvPoint(($srcSize.Width / 2), ($srcSize.Height / 2))
37. while ( [OpenCvSharp.CvWindow]::WaitKey(10) -lt 0 ) {
38. $iplImage = $camera.QueryFrame()
40. # 中心点を元にポイントの初期値を設定
41. for ($i = 0; $i -lt $contour.Length; $i++) {
42. $x = [int]($center.X * [System.Math]::Cos(2 * [System.Math]::PI * $i / $contour.Length) + $center.X)
43. $y = [int]($center.Y * [System.Math]::Sin(2 * [System.Math]::PI * $i / $contour.Length) + $center.Y)
44. $p = New-Object OpenCvSharp.CvPoint($x, $y)
45. $contour.Set($i, $p)
46. }
47. # グレースケールに変換
48. [OpenCvSharp.Cv]::CvtColor($iplImage, $srcIplImage, [OpenCvSharp.ColorConversion]::BgraToGray)
50. #　ぼかす
51. $srcIplImage.Smooth($srcIplImage, [OpenCvSharp.SmoothType]::Blur, $smooth)
53. # 二値化
54. $srcIplImage.Threshold($dstIplImage, $threshold, 255, [OpenCvSharp.ThresholdType]::Binary)
56. #　領域検知
57. $dstIplImage.SnakeImage($contour, $alpha, $beta, $gamma, $size, $tremCriteria, $true)
59. #　領域中の4点の座標を取得
60. $str1 = [String]::Format("1 : (x = {0}, y = {1})", $contour.Get(1).X, $contour.Get(1).Y)
61. $str25 = [String]::Format("25 : (x = {0}, y = {1})", $contour.Get(25).X, $contour.Get(25).Y)
62. $str50 = [String]::Format("50 : (x = {0}, y = {1})", $contour.Get(50).X, $contour.Get(50).Y)
63. $str75 = [String]::Format("75 : (x = {0}, y = {1})", $contour.Get(75).X, $contour.Get(75).Y)
65. #　ポイントを線で結んで描写
66. for ($i = 0; $i -lt ($contour.Length - 1); $i++) {
67. #　選んだ4点だけ　赤　それ以外は　青
68. if ($i -eq 1 -or $i -eq 25 -or $i -eq 50 -or $i -eq 75) {
69. $iplImage.Line($contour[$i], $contour[($i + 1)], $colorPoint, 6)
70. } else {
71. $iplImage.Line($contour[$i], $contour[($i + 1)], $colorLine, 3)
72. }
73. }
74. # 最初の点と最後の点を結ぶ
75. $iplImage.Line($contour[($contour.Length -1)], $contour[0], $colorLine, 3)
77. #　座標をウィンドウに描写
78. $iplImage.PutText($str1, $point1, $font, $colorString)
79. $iplImage.PutText($str25, $point25, $font, $colorString)
80. $iplImage.PutText($str50, $point50, $font, $colorString)
81. $iplImage.PutText($str75, $point75, $font, $colorString)
83. $window.Image = $iplImage
85. #　連続でループするとCPUをたくさん喰うので3秒間をあける
86. Start-Sleep 3
87. }
89. $iplImage.Dispose()
90. $srcIplImage.Dispose()
91. $dstIplImage.Dispose()
92. $window.Dispose()
93. $camera.Dispose()