AForge.Net 如何去除图片中的灰底

[zyqzyy]

AForge.Net 如何去除图片中的灰底？让图片中的文字更清晰，如下图：

[水哥阿乐]

建议楼主参考一下.net的GDI+方面，重点关注一下GDI+的滤色部分

[zyqzyy]

原图见一楼，去灰底效果如下图：

应用 AForge.Net 解决，代码如下：
Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click

Dim ImagePath As String
Dim dlg As New OpenFileDialog
If dlg.ShowDialog = Windows.Forms.DialogResult.OK Then
ImagePath = dlg.FileName
Else
Return
End If

Dim img As Bitmap = System.Drawing.Bitmap.FromFile(ImagePath)
Dim NewBitmap As Bitmap
Dim Oldimage As System.Drawing.Bitmap
Dim t As Date = Date.Now()

Try
Dim CloneRect As New Rectangle(0, 0, img.Width, img.Height)
Oldimage = img.Clone(CloneRect, PixelFormat.Format8bppIndexed) '从这个API文档页面可以看出，SobolEdgeDetector过滤器只支持8bpp灰度图像

Dim filter As AForge.Imaging.Filters.BradleyLocalThresholding = New AForge.Imaging.Filters.BradleyLocalThresholding()
NewBitmap = filter.Apply(Oldimage)
Application.DoEvents()
Me.PictureBox2.SizeMode = PictureBoxSizeMode.Zoom
Me.PictureBox2.Image = NewBitmap
Catch ex As Exception
MsgBox(ex.Message)
End Try
MsgBox("耗时: " & (Date.Now - t).TotalSeconds & " 秒")
End Sub

[zyqzyy]

能否介绍个例子？

[水哥阿乐]

是的还不错了,版本尽量高点,对比度太小了,处理效果也不会好的,会无端生成水渍的,有能力的话再去个噪