VB获取二值图重心求点评今天下午为了获取骨架图形不变矩，想到先获取图形重心。然后居然根据初中学的杠杆原
VB获取二值图重心求点评
今天下午为了获取骨架图形不变矩，想到先获取图形重心。然后居然根据初中学的杠杆原理构造了一条无重量的水平刚体线迭代计算骨架重心。最后好像成功了。不知道有没有错误，希望大家指点。
另存为Module1.bas文件
- VB code
Attribute VB_Name = "Module1"Option ExplicitType WeightPoint '受力点的重心位置和重量 X As Double Y As Double Weight As LongEnd TypeType LineDataStruct O As WeightPoint '返回值 'A和B 的重心位置O和重量 AX1Y1 As WeightPoint 'A点 BX2Y2 As WeightPoint 'B点 AB As Double '线段AB的长度，A、B两点间的欧氏距离 BO As Double '线段BO的长度 '以下用于解直线方程 X1EqualX2 As Boolean '当AX1Y1.X = BX2Y2.X时True,AB两点所在直线为 x轴值=X1，否则 y轴值=l * x轴值 + d l As Double 'y轴值=l * x轴值 + d d As Double 'y轴值=l * x轴值 + d '以下用于解二次方程 a As Double b As Double c As DoubleEnd TypePublic LineData As LineDataStructPublic CGOfImagePoints As WeightPoint '二值图像点阵的重心和重量Public Sub GetWeightPointOfAAndB() Dim DistX As Double, DistY As Double 'A、B两点X、Y方向的街区距离 DistX = LineData.BX2Y2.X - LineData.AX1Y1.X DistY = LineData.BX2Y2.Y - LineData.AX1Y1.Y LineData.AB = Sqr(DistX * DistX + DistY * DistY) LineData.BO = (LineData.AB * LineData.AX1Y1.Weight) / (LineData.AX1Y1.Weight + LineData.BX2Y2.Weight) If Abs(LineData.AX1Y1.X - LineData.BX2Y2.X) < 0.0000000000001 Then LineData.X1EqualX2 = True LineData.O.X = LineData.AX1Y1.X LineData.O.Y = LineData.BX2Y2.Y - Sqr(LineData.BO ^ 2 - DistX ^ 2) Else LineData.X1EqualX2 = False LineData.l = DistY / DistX LineData.d = LineData.AX1Y1.Y - LineData.l * LineData.AX1Y1.X LineData.a = LineData.l ^ 2 + 1 LineData.b = 2 * (LineData.l * (LineData.d - LineData.BX2Y2.Y) - LineData.BX2Y2.X) LineData.c = LineData.BX2Y2.X ^ 2 + (LineData.d - LineData.BX2Y2.Y) ^ 2 - LineData.BO ^ 2 LineData.O.X = (-LineData.b + Sqr(LineData.b ^ 2 - 4 * LineData.a * LineData.c)) / 2 / LineData.a If LineData.AX1Y1.X <= LineData.BX2Y2.X Then If LineData.O.X >= LineData.BX2Y2.X + 0.0000000000001 Then LineData.O.X = (-LineData.b - Sqr(LineData.b ^ 2 - 4 * LineData.a * LineData.c)) / 2 / LineData.a End If Else If LineData.O.X >= LineData.AX1Y1.X + 0.0000000000001 Then LineData.O.X = (-LineData.b - Sqr(LineData.b ^ 2 - 4 * LineData.a * LineData.c)) / 2 / LineData.a End If End If LineData.O.Y = LineData.l * LineData.O.X + LineData.d End If LineData.O.Weight = LineData.AX1Y1.Weight + LineData.BX2Y2.WeightEnd Sub
另存为Form1.frm文件
- VB code
VERSION 5.00Begin VB.Form Form1 AutoRedraw = -1 'True Caption = "Form1" ClientHeight = 3090 ClientLeft = 60 ClientTop = 450 ClientWidth = 4680 LinkTopic = "Form1" ScaleHeight = 3090 ScaleWidth = 4680 StartUpPosition = 3 '窗口缺省 Begin VB.CommandButton Command2 Caption = "GetCG" Height = 975 Left = 2160 TabIndex = 1 Top = 600 Width = 2415 End Begin VB.CommandButton Command1 Caption = "Init" Height = 1095 Left = 2160 TabIndex = 0 Top = 2040 Width = 2535 EndEndAttribute VB_Name = "Form1"Attribute VB_GlobalNameSpace = FalseAttribute VB_Creatable = FalseAttribute VB_PredeclaredId = TrueAttribute VB_Exposed = FalseOption ExplicitPrivate WeightP(100) As WeightPointPrivate Sub Command1_Click() Dim i As Long Randomize CLng(Date) + Timer For i = 0 To 3 WeightP(i).Weight = 500 * Rnd() WeightP(i).X = 800 * Rnd() WeightP(i).Y = 1000 * Rnd() Next iEnd SubPrivate Sub Command2_Click() Dim i As Long Let LineData.AX1Y1 = WeightP(0) For i = 100 To 1 Step -1 LineData.BX2Y2.Weight = WeightP(i).Weight LineData.BX2Y2.X = WeightP(i).X LineData.BX2Y2.Y = WeightP(i).Y Call GetWeightPointOfAAndB Let LineData.AX1Y1 = LineData.O Next i Form1.Print "Weight："; LineData.O.Weight Form1.Print "X："; LineData.O.X Form1.Print "Y："; LineData.O.YEnd Sub
完整工程下载：http://download.csdn.net/detail/dianyancao/4059483
[解决办法]
这个新颖，只听过物体图形的重心，没有听过二值图的重心