AR
第一节 临摹
小明经常临摹同桌小美的画作。
美术课上，老师表扬了小美的新作。
图1.1 小美的作品《蒙娜·毛虫的微笑》
临，是照着原作画；摹，是用薄纸张蒙在原作上面画。
第二节 借画
小明随后借来了小美的画。
但他觉得这样摹着画甚是无趣。
图2.1 未完成的临摹
一般地，临摹耐心与纸张透明度成正比。
第三节 涂鸦
小明认为这只毛虫太孤单了。
然后，他的涂鸦怪兽就蹦了出来。
图3.1 《蒙娜·毛虫与她的怪兽》
涂鸦，随意地涂抹色彩与线条。
第四节 黑白
小美的哥哥和小明是好朋友，他叫大美。
大美有个AR程序，它可以计算图像的黑与白。
图4.1 黑白版《蒙娜·毛虫的微笑》
黑白阈值划分可以基于RGB颜色空间也可以基于HSV颜色空间。
VB.NETPublic Class ImageProcessClass
''' <summary>
''' 基于RGB根据指定阈值判断两个颜色是否相近
''' </summary>
Public Function CompareRGB(ByVal Color1 As Color, ByVal Color2 As Color, ByVal Distance As Single) As Boolean
Dim r As Integer = Int(Color1.R) - Int(Color2.R)
Dim g As Integer = Int(Color1.G) - Int(Color2.G)
Dim b As Integer = Int(Color1.B) - Int(Color2.B)
Dim absDis As Integer = Math.Sqrt(r * r + g * g + b * b)
If absDis < Distance Then
Return True
Else
Return False
End If
End Function
''' <summary>
''' 基于HSB根据指定阈值判断两个颜色是否相近
''' </summary>
Public Function CompareHSB(ByVal Color1 As Color, ByVal Color2 As Color, ByVal Distance As Single) As Boolean
'Dim h As Single = (Color1.GetHue - Color2.GetHue) / 360
'Dim s As Single = Color1.GetSaturation - Color2.GetSaturation
'Dim b As Single = Color1.GetBrightness - Color2.GetBrightness
'Dim absDis As Single = Math.Sqrt(h * h + s * s + b * b)
'If absDis < Distance Then
' Return True
'Else
' Return False
'End If
Dim h1 As Single = Color1.GetHue / 360
Dim s1 As Single = Color1.GetSaturation
Dim b1 As Single = Color1.GetBrightness
Dim h2 As Single = Color2.GetHue / 360
Dim s2 As Single = Color2.GetSaturation
Dim b2 As Single = Color2.GetBrightness
Dim absDis As Single = (h1 * h2 + s1 * s2 + b1 * b2) / (Math.Sqrt(h1 * h1 + s1 * s1 + b1 * b1) * Math.Sqrt(h2 * h2 + s2 * s2 + b2 * b2))
If absDis > Distance / 5 + 0.8 Then
Return True
Else
Return False
End If
End Function
''' <summary>
''' 返回指定颜色的中值
''' </summary>
Public Function gethHD(ByVal color1 As Color)
Dim HD, r, g, b As Integer
r = color1.R
g = color1.G
b = color1.B
HD = (r + g + b) / 3
Return HD
End Function
''' <summary>
''' 返回指定位图的颜色数组
''' </summary>
''' <param name="gBitmap"></param>
''' <returns></returns>
Public Function GetColorArr(ByRef gBitmap As Bitmap) As Color(,)
Dim TempArr(gBitmap.Width - 1, gBitmap.Height - 1) As Color
For i = 0 To gBitmap.Width - 1
For j = 0 To gBitmap.Height - 1
TempArr(i, j) = gBitmap.GetPixel(i, j)
Next
Next
Return TempArr
End Function
''' <summary>
''' 返回指定区域的屏幕图像
''' </summary>
''' <param name="gX"></param>
''' <param name="gY"></param>
''' <param name="gWidth"></param>
''' <param name="gHeight"></param>
''' <returns></returns>
Public Function GetScreenImage(ByVal gX As Integer, ByVal gY As Integer, ByVal gWidth As Integer, ByVal gHeight As Integer) As Bitmap
Dim ResultBitmap As New Bitmap(gWidth, gHeight)
Using pg As Graphics = Graphics.FromImage(ResultBitmap)
pg.CopyFromScreen(gX, gY, 0, 0, New Size(gWidth, gHeight))
End Using
Return ResultBitmap
End Function
''' <summary>
''' 返回指定文字生成的位图
''' </summary>
''' <param name="gString"></param>
''' <param name="gFont"></param>
''' <param name="gWidth"></param>
''' <param name="gHeight"></param>
''' <returns></returns>
Public Function GetTextImage(ByVal gString As String, ByVal gFont As Font, ByVal gWidth As Integer, ByVal gHeight As Integer) As Bitmap
Dim ResultBitmap As New Bitmap(gWidth, gHeight)
Using pg = Graphics.FromImage(ResultBitmap)
pg.SmoothingMode = Drawing2D.SmoothingMode.AntiAlias '抗锯齿
pg.DrawString(gString, gFont, Brushes.Black, 0, 0)
End Using
Return ResultBitmap
End Function
''' <summary>
''' 返回指定图位图的二值化图像
''' </summary>
''' <param name="gBitmap"></param>
''' <param name="gSplitNum"></param>
''' <returns></returns>
Public Function GetThresholdImage(ByVal gBitmap As Bitmap, ByVal gSplitNum As Single, Optional IsHSB As Boolean = False) As Bitmap
Dim ResultBitmap As New Bitmap(gBitmap.Width, gBitmap.Height)
Dim ColorArr(,) = GetColorArr(gBitmap)
Dim TempHD As Integer
Dim IsOverThreshold = Function(ByVal C1 As Color, ByVal gNum As Single)
TempHD = gethHD(C1)
Return (If(IsHSB, (C1.GetHue / 360 + C1.GetSaturation + C1.GetBrightness) / 3 < gNum,
TempHD < gNum))
End Function
For i = 0 To gBitmap.Width - 1
For j = 0 To gBitmap.Height - 1
ResultBitmap.SetPixel(i, j, If(IsOverThreshold(ColorArr(i, j), gSplitNum), Color.Black, Color.White))
Next
Next
Return ResultBitmap
End Function
''' <summary>
''' 返回指定位图的轮廓图像
''' </summary>
''' <param name="gBitmap"></param>
''' <param name="gDistance"></param>
''' <returns></returns>
Public Function GetOutLineImage(ByVal gBitmap As Bitmap, ByVal gDistance As Single, Optional IsHSB As Boolean = False) As Bitmap
Dim xArray2() As Short = {0, 1, 0, -1}
Dim yArray2() As Short = {-1, 0, 1, 0}
'Dim ResultBitmap As New Bitmap(gBitmap) '在原图的基础上绘图
Dim ResultBitmap As New Bitmap(gBitmap.Width, gBitmap.Height)
Dim Color1, Color2 As Color
Dim CompareColor = Function(ByVal C1 As Color, ByVal C2 As Color, ByVal Distance As Single)
Return If(IsHSB,
CompareHSB(Color1, Color2, Distance),
CompareRGB(Color1, Color2, Distance))
End Function
Dim CompareColorExtra = Function(ByVal C1 As Color, ByVal C2 As Color)
Return If(IsHSB,
Color1.GetBrightness - Color2.GetBrightness > 0,
gethHD(Color1) - gethHD(Color2) > 0)
End Function
Dim ColorArr(,) = GetColorArr(gBitmap)
For i = 1 To gBitmap.Width - 2
For j = 1 To gBitmap.Height - 2
ResultBitmap.SetPixel(i, j, Color.White)
Color1 = ColorArr(i, j)
For p = 0 To 3
Color2 = ColorArr(i + xArray2(p), j + yArray2(p))
If Not CompareColor(Color1, Color2, gDistance) And CompareColorExtra(Color1, Color2) Then
ResultBitmap.SetPixel(i, j, Color.Black)
' ResultBitmap.SetPixel(i, j, ColorArr(i, j))
End If
Next
Next
Next
Return ResultBitmap
End Function
''' <summary>
''' 返回指定位图的空心图像
''' </summary>
''' <param name="gBitmap"></param>
''' <returns></returns>
Public Function GetAroundImage(gBitmap As Bitmap)
Dim ResultBitmap As New Bitmap(gBitmap.Width, gBitmap.Height)
Dim ImageBolArr(,) As Integer = GetImageBol(gBitmap)
For i = 0 To gBitmap.Width - 1
For j = 0 To gBitmap.Height - 1
If ImageBolArr(i, j) = 1 AndAlso CheckPointAround(ImageBolArr, i, j) = False Then
ResultBitmap.SetPixel(i, j, Color.Black)
Else
ResultBitmap.SetPixel(i, j, Color.White)
End If
Next
Next
Return ResultBitmap
End Function
''' <summary>
''' 返回指定位图的反相图像
''' </summary>
''' <param name="gBitmap"></param>
''' <returns></returns>
Public Function GetInvertImage(gBitmap As Bitmap)
Dim ResultBitmap As New Bitmap(gBitmap.Width, gBitmap.Height)
Dim ImageBolArr(,) As Integer = GetImageBol(gBitmap)
For i = 0 To gBitmap.Width - 1
For j = 0 To gBitmap.Height - 1
If ImageBolArr(i, j) = 1 Then
ResultBitmap.SetPixel(i, j, Color.White)
Else
ResultBitmap.SetPixel(i, j, Color.Black)
End If
Next
Next
Return ResultBitmap
End Function
''' <summary>
''' 返回指定位图的色块图像
''' </summary>
''' <param name="gBitmap"></param>
''' <returns></returns>
Public Function GetLumpImage(gBitmap As Bitmap, Optional Range As Integer = 10)
Dim ResultBitmap As New Bitmap(gBitmap.Width, gBitmap.Height)
Dim ColorArr(,) = GetColorArr(gBitmap)
Dim R, G, B As Integer
For i = 0 To gBitmap.Width - 1
For j = 0 To gBitmap.Height - 1
R = Int(ColorArr(i, j).R / Range) * Range
G = Int(ColorArr(i, j).G / Range) * Range
B = Int(ColorArr(i, j).B / Range) * Range
ResultBitmap.SetPixel(i, j, Color.FromArgb(R, G, B))
Next
Next
Return ResultBitmap
End Function
''' <summary>
''' 返回指定位图的二值化数据
''' </summary>
''' <param name="gBitmap"></param>
''' <returns></returns>
Private Function GetImageBol(ByVal gBitmap As Bitmap) As Integer(,)
Dim ResultArr(gBitmap.Width - 1, gBitmap.Height - 1) As Integer
For i = 0 To gBitmap.Width - 1
For j = 0 To gBitmap.Height - 1
If Not gBitmap.GetPixel(i, j).Equals(Color.FromArgb(255, 255, 255)) Then
ResultArr(i, j) = 1
Else
ResultArr(i, j) = 0
End If
Next
Next
Return ResultArr
End Function
''' <summary>
''' 检查一个点是否被包围
''' </summary>
''' <param name="BolArr"></param>
''' <param name="x"></param>
''' <param name="y"></param>
''' <returns></returns>
Private Function CheckPointAround(BolArr As Integer(,), ByVal x As Integer, ByVal y As Integer) As Boolean
If Not (x > 0 And y > 0 And x < BolArr.GetUpperBound(0) And y < BolArr.GetUpperBound(1)) Then Return True
If BolArr(x - 1, y) = 1 And BolArr(x + 1, y) = 1 And BolArr(x, y - 1) = 1 And BolArr(x, y + 1) = 1 Then
Return True '当前点为实体内部
Else
Return False '当前点为实体边缘
End If
End Function
End Class
VB.NET
C#using Microsoft.VisualBasic;
using System;
using System.Collections;
using System.Collections.Generic;
using System.Data;
using System.Diagnostics;
public class SequenceManagerClass
{
/// <summary>
/// 绘制序列的List
/// </summary>
public List<PointSequenceClass> SequenceList;
public SequenceManagerClass(int[,] BolArr)
{
SequenceList = new List<PointSequenceClass>();
CalculateSequence(BolArr);
}
private void CreateNewSequence()
{
SequenceList.Add(new PointSequenceClass());
}
private void AddPoint(PointF aPoint)
{
SequenceList.Last.PointList.Add(aPoint);
}
int[] xArray = {
-1,
0,
1,
1,
1,
0,
-1,
-1
};
int[] yArray = {
-1,
-1,
-1,
0,
1,
1,
1,
};
bool NewStart;
private void CheckMove(ref int[,] BolArr, int x, int y, int StepNum)
{
Application.DoEvents();
if (StepNum > 200)
return;
int xBound = BolArr.GetUpperBound(0);
int yBound = BolArr.GetUpperBound(1);
int dx = 0;
int dy = 0;
int AroundValue = GetAroundValue(ref BolArr, x, y);
if (AroundValue > 2 && AroundValue < 8) {
return;
}
for (i = 0; i <= 7; i++) {
dx = x + xArray[i];
dy = y + yArray[i];
if (!(dx > 0 & dy > 0 & dx < xBound & dy < yBound)) {
return;
} else if (BolArr[dx, dy] == 1) {
BolArr[dx, dy] = 0;
if (NewStart == true) {
this.CreateNewSequence();
this.AddPoint(new PointF(dx, dy));
NewStart = false;
} else {
this.AddPoint(new PointF(dx, dy));
}
CheckMove(ref BolArr, dx, dy, StepNum + 1);
NewStart = true;
}
}
}
private void CalculateSequence(int[,] BolArr)
{
int xCount = BolArr.GetUpperBound(0);
int yCount = BolArr.GetUpperBound(1);
Point CP = new Point(xCount / 2, yCount / 2);
int R = 0;
for (R = 0; R <= xCount > yCount ? xCount : yCount; R++) {
for (Theat = 0; Theat <= Math.PI * 2; Theat += 1 / R) {
int dx = CP.X + R * Math.Cos(Theat);
int dy = CP.Y + R * Math.Sin(Theat);
if (!(dx > 0 & dy > 0 & dx < xCount & dy < yCount))
continue;
if (BolArr[dx, dy] == 1) {
BolArr[dx, dy] = 0;
this.CreateNewSequence();
this.AddPoint(new PointF(dx, dy));
CheckMove(ref BolArr, dx, dy, 0);
NewStart = true;
}
}
}
}
private int GetAroundValue(ref int[,] BolArr, int x, int y)
{
int dx = 0;
int dy = 0;
int ResultValue = 0;
int xBound = BolArr.GetUpperBound(0);
int yBound = BolArr.GetUpperBound(1);
for (i = 0; i <= 7; i++) {
dx = x + xArray[i];
dy = y + yArray[i];
if (dx > 0 & dy > 0 & dx < xBound & dy < yBound) {
if (BolArr[dx, dy] == 1) {
ResultValue += 1;
}
}
}
return ResultValue;
}
}
public class PointSequenceClass
{
public List<PointF> PointList = new List<PointF>();
}
C#
第五节 线条
AR程序还可以计算图像组成的线条。
参考线条序列，小明就不会不知道如何下笔了。
图5.1 程序实现自动线条
定义一个SequenceManager类，它用以识别线条、并管理PointSequence类。
VB.NETPublic Class SequenceManagerClass
''' <summary>
''' 绘制序列的List
''' </summary>
Public SequenceList As List(Of PointSequenceClass)
Public Sub New(BolArr(,) As Integer)
SequenceList = New List(Of PointSequenceClass)
CalculateSequence(BolArr)
End Sub
Private Sub CreateNewSequence()
SequenceList.Add(New PointSequenceClass)
End Sub
Private Sub AddPoint(aPoint As PointF)
SequenceList.Last.PointList.Add(aPoint)
End Sub
Dim xArray() As Integer = {-1, 0, 1, 1, 1, 0, -1, -1}
Dim yArray() As Integer = {-1, -1, -1, 0, 1, 1, 1, 0}
Dim NewStart As Boolean
Private Sub CheckMove(ByRef BolArr(,) As Integer, ByVal x As Integer, ByVal y As Integer, ByVal StepNum As Integer)
Application.DoEvents()
If StepNum > 200 Then Return
Dim xBound As Integer = BolArr.GetUpperBound(0)
Dim yBound As Integer = BolArr.GetUpperBound(1)
Dim dx, dy As Integer
Dim AroundValue As Integer = GetAroundValue(BolArr, x, y)
If AroundValue > 2 AndAlso AroundValue < 8 Then
Return
End If
For i = 0 To 7
dx = x + xArray(i)
dy = y + yArray(i)
If Not (dx > 0 And dy > 0 And dx < xBound And dy < yBound) Then
Return
ElseIf BolArr(dx, dy) = 1 Then
BolArr(dx, dy) = 0
If NewStart = True Then
Me.CreateNewSequence()
Me.AddPoint(New PointF(dx, dy))
NewStart = False
Else
Me.AddPoint(New PointF(dx, dy))
End If
CheckMove(BolArr, dx, dy, StepNum + 1)
NewStart = True
End If
Next
End Sub
Private Sub CalculateSequence(BolArr(,) As Integer)
Dim xCount As Integer = BolArr.GetUpperBound(0)
Dim yCount As Integer = BolArr.GetUpperBound(1)
Dim CP As New Point(xCount / 2, yCount / 2)
Dim R As Integer = 0
For R = 0 To If(xCount > yCount, xCount, yCount)
For Theat = 0 To Math.PI * 2 Step 1 / R
Dim dx As Integer = CP.X + R * Math.Cos(Theat)
Dim dy As Integer = CP.Y + R * Math.Sin(Theat)
If Not (dx > 0 And dy > 0 And dx < xCount And dy < yCount) Then Continue For
If BolArr(dx, dy) = 1 Then
BolArr(dx, dy) = 0
Me.CreateNewSequence()
Me.AddPoint(New PointF(dx, dy))
CheckMove(BolArr, dx, dy, 0)
NewStart = True
End If
Next
Next
End Sub
Private Function GetAroundValue(ByRef BolArr(,) As Integer, ByVal x As Integer, ByVal y As Integer) As Integer
Dim dx, dy, ResultValue As Integer
Dim xBound As Integer = BolArr.GetUpperBound(0)
Dim yBound As Integer = BolArr.GetUpperBound(1)
For i = 0 To 7
dx = x + xArray(i)
dy = y + yArray(i)
If dx > 0 And dy > 0 And dx < xBound And dy < yBound Then
If BolArr(dx, dy) = 1 Then
ResultValue += 1
End If
End If
Next
Return ResultValue
End Function
End Class
Public Class PointSequenceClass
Public PointList As New List(Of PointF)
End Class
VB.NET
C#
using Microsoft.VisualBasic;
using System;
using System.Collections;
using System.Collections.Generic;
using System.Data;
using System.Diagnostics;
public class SequenceManagerClass
{
/// <summary>
/// 绘制序列的List
/// </summary>
public List<PointSequenceClass> SequenceList;
public SequenceManagerClass(int[,] BolArr)
{
SequenceList = new List<PointSequenceClass>();
CalculateSequence(BolArr);
}
private void CreateNewSequence()
{
SequenceList.Add(new PointSequenceClass());
}
private void AddPoint(PointF aPoint)
{
SequenceList.Last.PointList.Add(aPoint);
}
int[] xArray = {
-1,
0,
1,
1,
1,
0,
-1,
-1
};
int[] yArray = {
-1,
-1,
-1,
0,
1,
1,
1,
};
bool NewStart;
private void CheckMove(ref int[,] BolArr, int x, int y, int StepNum)
{
Application.DoEvents();
if (StepNum > 200)
return;
int xBound = BolArr.GetUpperBound(0);
int yBound = BolArr.GetUpperBound(1);
int dx = 0;
int dy = 0;
int AroundValue = GetAroundValue(ref BolArr, x, y);
if (AroundValue > 2 && AroundValue < 8) {
return;
}
for (i = 0; i <= 7; i++) {
dx = x + xArray[i];
dy = y + yArray[i];
if (!(dx > 0 & dy > 0 & dx < xBound & dy < yBound)) {
return;
} else if (BolArr[dx, dy] == 1) {
BolArr[dx, dy] = 0;
if (NewStart == true) {
this.CreateNewSequence();
this.AddPoint(new PointF(dx, dy));
NewStart = false;
} else {
this.AddPoint(new PointF(dx, dy));
}
CheckMove(ref BolArr, dx, dy, StepNum + 1);
NewStart = true;
}
}
}
private void CalculateSequence(int[,] BolArr)
{
int xCount = BolArr.GetUpperBound(0);
int yCount = BolArr.GetUpperBound(1);
Point CP = new Point(xCount / 2, yCount / 2);
int R = 0;
for (R = 0; R <= xCount > yCount ? xCount : yCount; R++) {
for (Theat = 0; Theat <= Math.PI * 2; Theat += 1 / R) {
int dx = CP.X + R * Math.Cos(Theat);
int dy = CP.Y + R * Math.Sin(Theat);
if (!(dx > 0 & dy > 0 & dx < xCount & dy < yCount))
continue;
if (BolArr[dx, dy] == 1) {
BolArr[dx, dy] = 0;
this.CreateNewSequence();
this.AddPoint(new PointF(dx, dy));
CheckMove(ref BolArr, dx, dy, 0);
NewStart = true;
}
}
}
}
private int GetAroundValue(ref int[,] BolArr, int x, int y)
{
int dx = 0;
int dy = 0;
int ResultValue = 0;
int xBound = BolArr.GetUpperBound(0);
int yBound = BolArr.GetUpperBound(1);
for (i = 0; i <= 7; i++) {
dx = x + xArray[i];
dy = y + yArray[i];
if (dx > 0 & dy > 0 & dx < xBound & dy < yBound) {
if (BolArr[dx, dy] == 1) {
ResultValue += 1;
}
}
}
return ResultValue;
}
}
public class PointSequenceClass
{
public List<PointF> PointList = new List<PointF>();
}
C#
第六节 投影
最后，AR程序将计算后的图像投影到屏幕上。
图像与现实影像真实镶嵌，小明就可以照着屏幕临摹。
图6.1 未经PS的AR演示
事实上，小明若使用沉浸式AR眼镜，他会得到更佳的体验。
附录
早期博客：程序实现自动绘图
早期博客：更优秀的绘图程序