vb.net读取picturebox所有像素

[uuicczxl]

vb6 可以用 getbits 速度还可以

vb.net 用什么方法读取所有像素速度快呢

[wuyq11]

Bitmap.GetPixel

[uuicczxl]

详细点好吗 给分

[yifan__]

顶一个，我也想知道额

[lang_csdn]

对这方面没有什么研究，是不是根据x,y轴，循环使用GetPixel读取吧！

[uuicczxl]

.net 能用getpixel 还说什么了

[lang_csdn]

[Quote=引用 5 楼 uuicczxl 的回复:]
.net 能用getpixel 还说什么了
[/Quote]

.net 也可以使用getpixel api的

[laviewpbt]

[Quote=引用 1 楼 wuyq11 的回复:]
Bitmap.GetPixel
[/Quote]

钻石给出这样的答案让我对CSDN的这种等级制度表示强烈的怀疑。

VB.NET中可以用LockBits

[uuicczxl]

[Quote=引用 6 楼 lang_csdn 的回复:]
引用 5 楼 uuicczxl 的回复:
.net 能用getpixel 还说什么了


.net 也可以使用getpixel  api的



[/Quote]


怎么用啊

[laviewpbt]

http://blog.csdn.net/laviewpbt/category/255592.aspx?PageNumber=2

vb.net中彩色图像数据的快速获取

[uuicczxl]

没这么难吧。。。

[lang_csdn]

Partial Public Class NativeMethods

'''Return Type: COLORREF->DWORD->unsigned int
'''hdc: HDC->HDC__*
'''x: int
'''y: int
<System.Runtime.InteropServices.DllImportAttribute("gdi32.dll", EntryPoint:="GetPixel")> _
Public Shared Function GetPixel(<System.Runtime.InteropServices.InAttribute()> ByVal hdc As Integer, ByVal x As Integer, ByVal y As Integer) As UInteger
End Function


<System.Runtime.InteropServices.DllImportAttribute("user32.dll", EntryPoint:="GetDC")> _
Public Shared Function GetDC(<System.Runtime.InteropServices.InAttribute()> ByVal hWnd As System.IntPtr) As System.IntPtr
End Function
End Class




Dim b As New System.Drawing.Bitmap("c:\1.jpg")
Dim g As System.Drawing.Graphics = System.Drawing.Graphics.FromImage(b)
Dim hdc As IntPtr = g.GetHdc


For x As Integer = 0 To 10
For y As Integer = 0 To 20
Debug.WriteLine(".NET" & b.GetPixel(x, y).ToArgb & " API: " & NativeMethods.GetPixel(hdc.ToInt32, x, y))
Next
Next


不过，我发现api的值，不能读取，可能是hdc的问题！准备吃饭了，希望高手帮我改一下！

[uuicczxl]

来人啊

[清晨曦月]

Public Class Form1
Dim bmp As Bitmap
Dim WithEvents but As Button
Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
but = New Button
Me.Controls.Add(but)
but.Location = Me.ClientSize - but.Size
bmp = Bitmap.FromFile("C:\Documents and Settings\zcsor\My Documents\My Pictures\远古.jpg")
Me.BackgroundImage = bmp
End Sub

Private Sub but_Click(ByVal sender As Object, ByVal e As System.EventArgs) Handles but.Click
'下面是用了GetPixel方法，如果图片比较大，那么应该用下面的LockBits方法。
Dim x As Integer = 0, y As Integer = 0
Debug.Print(Hex(bmp.GetPixel(x, y).ToArgb).PadLeft(8, "0") & " --- " & bmp.GetPixel(x, y).ToString)
x = 1
Debug.Print(Hex(bmp.GetPixel(x, y).ToArgb).PadLeft(8, "0") & " --- " & bmp.GetPixel(x, y).ToString)
x = 2
Debug.Print(Hex(bmp.GetPixel(x, y).ToArgb).PadLeft(8, "0") & " --- " & bmp.GetPixel(x, y).ToString)
'下面使用LockBits方法，一次性获取了全部数据，所以图片比较大的时候速度会明显更快一些。
Dim b As Drawing.Imaging.BitmapData = bmp.LockBits(Rectangle.Truncate(bmp.GetBounds(GraphicsUnit.Pixel)), Imaging.ImageLockMode.ReadOnly, bmp.PixelFormat)
Dim ptr As IntPtr = b.Scan0
Dim bytes As Integer = b.Stride * bmp.Height
Dim rgbValues(bytes - 1) As Byte
System.Runtime.InteropServices.Marshal.Copy(ptr, rgbValues, 0, bytes)
bmp.UnlockBits(b)
Debug.Print("b:" & rgbValues(0) & " " & "g:" & rgbValues(1) & " " & "r:" & rgbValues(2))
Debug.Print("b:" & rgbValues(3) & " " & "g:" & rgbValues(4) & " " & "r:" & rgbValues(5))
Debug.Print("b:" & rgbValues(6) & " " & "g:" & rgbValues(7) & " " & "r:" & rgbValues(8))
End Sub

End Class

[清晨曦月]

不过也有点问题，这里边总有个大范围寻址的问题。不知道哪位高人有更好的方法。但相对来讲还是后面的方法更快一些，有兴趣可以查看BitMap.GetPixel方法的源码，呵呵。另外带A通道的处理和这个稍有差异。