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这问题有点笼统,软糖来说说把:
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图像处理由System.Drawing命名空间负责。
主要是Bitmap类和Graphics类。
Bitmap表示一个位图,可以是BMP,JPG,PNG等文件。
装载位图
Dim 位图 As Bitmap = Bitmap.FromFile("C:\Image1.PNG")
Graphics表示一张画纸,能够进行绘制操作。
它可以被窗体、控件、位图调用CreateGraphics()方法来创建。
然后调用Graphics.Draw开头的一系列函数来绘制图像和图形,Fill开头的填充图形。
创建画纸并绘制位图
Dim 画纸 As Graphics = Me.CreateGraphics()
画纸.DrawImage(位图, 100, 100, 256, 256)
可以将上面三行放到Form1_Load中测试,把路径改一下,
还可以把Me改为能在上面绘图的控件的名称。
更多内容请看MSDN的System.Drawing命名空间。
如满意,请采纳,谢谢。
首先,还是谈谈图像像素时数据获取方面吧,点虐 中的图像相关类基本上都是基于GDI+的,因此,图像数据的获取其实也是调用GDI+的一些函数。这个函数就是LockBits,在vb点虐 中彩色图像数据的快速获取 一文中,我们是调用了Marshal.Copy把LockBits锁定的内存数据拷贝到数据中,然后对数组中的值进行处理。这样做主要的原因是VB.NET不好直接访问内存(Marshal.ReadByte之类的函数不适合用于大型的循环中)。那么,这就造成了2个不好的事情,第一:在同一时间需要2倍于图像数据量的内存,第二:内存数据拷贝到数据,以及处理后再把数组的数据拷贝会内存中都是会减低速度的。作为一种改进,我们应该充分利用LockBits的功能。LockBits中的LockMode中有一种模式为ImageLockMode.UserInputBuffer,该模式下需要用户先申请内存,然后在把图像数据按照相关格式填充如这个内存中。这样,就可以先定义个数组,然后把图像数据填充到这个数组中,就避免了来回拷贝的耗时了,简单示例代码如下:
Dim BmpData As New BitmapData
Stride = ((Bmp.Width * 3 + 3) And HFFFFFFFC)
Dim PixleValue(Stride * Bmp.Height) As Byte
Dim Hanlde As GCHandle = GCHandle.Alloc(PixleValue, GCHandleType.Pinned)
BmpData.Scan0 = Hanlde.AddrOfPinnedObject()
Imports System
Imports System.Drawing
Imports System.Drawing.Imaging
Imports System.Runtime.InteropServices
''' summary
''' Summary description for TextShadow
''' /summary
''' remarks/remarks
Public Class gaoshiBLUR
Public newbmp As Bitmap
StructLayout(LayoutKind.Explicit) Structure rgbA
FieldOffset(0) Public R As Byte
FieldOffset(1) Public G As Byte
FieldOffset(2) Public B As Byte
FieldOffset(3) Public A As Byte
FieldOffset(0) Public col As Integer
End Structure
Private m_radius As Integer = 5
''' summary
''' 高斯卷积矩阵
''' /summary
''' remarks/remarks
Private gaussMatrix As Integer()
''' summary
''' 卷积核
''' /summary
''' remarks/remarks
Private nuclear As Integer = 0
''' summary
''' 模糊半径
''' /summary
''' value/value
''' returns/returns
''' remarks/remarks
Public Property Radius() As Integer
Get
Return m_radius
End Get
Set(ByVal Value As Integer)
If (m_radius Value) Then
m_radius = Value
MakeGaussMatrix()
End If
End Set
End Property
''' summary
''' 高斯模糊
''' /summary
''' param name="bmp"要处理的图像/param
''' remarks/remarks
Public Sub MaskShadow(ByVal bmp As Bitmap)
If nuclear = 0 Then MakeGaussMatrix()
Dim rt As Rectangle = New Rectangle(0, 0, bmp.Width, bmp.Height)
' 克隆临时位图,作为卷积源
Dim tmp As Bitmap = bmp.Clone()
Dim dest As BitmapData = bmp.LockBits(rt, ImageLockMode.WriteOnly, PixelFormat.Format32bppArgb)
Dim source As BitmapData = tmp.LockBits(rt, ImageLockMode.ReadOnly, PixelFormat.Format32bppArgb)
Debug.Print(Radius)
Debug.Print(dest.Width.ToString)
Debug.Print(nuclear)
Dim Number As Integer = (bmp.Height * dest.Stride - 1) / 4 ' 图像数据元素的个数,注意点虐 中数组下标是从0开始的
Dim bmpdata(Number) As Integer
Dim tmpdata(Number) As Integer
Dim TMPrgb(Number) As rgbA '临时参考颜色
Dim BMPrgb(Number) As rgbA '计算结果后的颜色
'ReDim bmpdata(Number)
'ReDim TMPrgb(Number)
Marshal.Copy(source.Scan0, tmpdata, 0, Number)
Dim i As Long
Dim j As Long
j = Number
Dim w, h As Long
Dim yi, xi As Long
Dim iw, ih, iiw, iih, iii As Long
Dim k As Long
Dim nn As Integer = (Radius * 2 + 1) ^ 2
Dim n As Integer = Radius * 2 + 1
w = bmp.Width
h = bmp.Height
' System.Array.Copy(TMPrgb, tmpdata, j)
For i = 0 To j
TMPrgb(i).col = tmpdata(i)
Next i
i = 0
For i = 0 To j
ih = Int(i / w)
iw = i - ih * w
Dim r As Double = 0
Dim g As Double = 0
Dim b As Double = 0
Dim a As Double = 0
Dim weight As Double
For k = 0 To nn
'需要解决的是周边遍历颜色值然后相加(r=r1*weight1+r2*weight2+r3*weight3+r4*weight4+r5*weight5+...r*weight)
yi = Int(k / n)
xi = k - yi * n
yi -= Radius
xi -= Radius
iiw = iw + xi
iih = ih + yi
'yi = Int(k / n)
'xi = k - yi * n
'iih = ih + yi - Radius
'iiw = iw + xi - Radius
If (iiw 0 OrElse iih 0) Or (iiw w - 1 OrElse iih h - 1) Then
iiw = iw
iih = ih
iii = i
Else
iii = iih * w
iii += iiw
End If
weight = gaussMatrix(k) / 1000
r += TMPrgb(iii).R * weight
g += TMPrgb(iii).G * weight
b += TMPrgb(iii).B * weight
a += TMPrgb(iii).A * weight
Next
'TMPrgb(i).col = tmpdata(i)
'r = TMPrgb(i).R * weight
'g = TMPrgb(i).G * weight
'b = TMPrgb(i).B * weight
BMPrgb(i).R = IIf(r 255, 255, r)
BMPrgb(i).G = IIf(g 255, 255, g)
BMPrgb(i).B = IIf(b 255, 255, b)
BMPrgb(i).A = IIf(a 255, 255, a)
bmpdata(i) = BMPrgb(i).col
'Debug.Print(TMPrgb(i).R)
Next
Marshal.Copy(bmpdata, 0, dest.Scan0, Number)
tmp.UnlockBits(source)
bmp.UnlockBits(dest)
newbmp = bmp.Clone
tmp.Dispose()
' End Try
End Sub
''' summary
''' 高斯卷积矩阵
''' /summary
''' remarks/remarks
Protected Sub MakeGaussMatrix()
Dim Q As Double = Radius / 2
If (Q = 0.0) Then Q = 0.1
Dim n As Integer = Radius * 2 + 1
Dim index As Integer = 0
nuclear = 0
ReDim gaussMatrix(n * n)
Dim x As Integer
Dim y As Integer
For x = -Radius To Radius
For y = -Radius To Radius
gaussMatrix(index) = Math.Round(Math.Exp(-((x * x + y * y)) / (2.0 * Q * Q)) / (2.0 * Math.PI * Q * Q) * 1000.0)
nuclear += gaussMatrix(index)
index += 1
Next
Next
End Sub
End Class
使用方法.
Dim bmp As Bitmap = PictureBox1.Image.Clone
Dim x As New gaoshiBLUR
x.Radius = 30
x.MaskShadow(bmp)
PictureBox2.Image = x.newbmp.Clone
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