专家坐堂-[分享]图片去除灰底、锐化、柔化、图片无损压缩、任意位置添加水印等等Foxtable(狐表) - 新一代数据库软件，完美融合Access、Foxpro、Excel、vb.net之优势，人人都能掌握的快速软件开发工具!

在Foxtable中新建一个窗口，添加一个按钮、一个图片框

按钮写入 VB.Net Laplacian(拉普拉斯)算子图片锐化代码如下：

Dim ImagePath As String

Dim dlg As OpenFileDialog = Me.OpenFileDialog1

If dlg.ShowDialog = Windows.Forms.DialogResult.OK Then

ImagePath = dlg.FileName

Else

Return

End If

Dim tempImage As Image = Image.FromFile(ImagePath)

Dim Height As Integer

Height = tempImage.Height

Dim width As Integer

width = tempImage.Width

NewBitmap = New Bitmap(width, Height)

Dim OldBitmap As Bitmap = New Bitmap(ImagePath)

Dim t As Date = Date.Now

Try

\'在使用本函数对彩色图像进行锐化处理时,应该选择{0,-1,0,-1,5,-1,0,-1,0}作为模板,所用模板能在最大限度保证彩色图像不失真的前提下,使图像轮廓线更清晰。

Dim pixel As Color

\'Dim Laplacian() As Integer = {0, -1, 0, -1, 5, -1, 0, -1, 0}

Dim Laplacian() As Integer = {-1, -1, -1, -1, 9, -1, -1, -1, -1}

For x As Integer = 1 To width - 2

For y As Integer = 1 To Height - 2

Me.ProgressBar1.Value = x + y

Dim r As Integer = 0

Dim g As Integer = 0

Dim b As Integer = 0

Dim index As Integer = 0

For col As Integer = -1 To 1 \'用Laplacian(拉普拉斯)算子计算当前坐标处像素的上、下、左、右及四角共8处（英文：8 neighbor）的像素值

For row As Integer = -1 To 1

pixel = OldBitmap.GetPixel(x + row, y + col)

r = r + pixel.R * Laplacian(index)

g = g + pixel.G * Laplacian(index)

b = b + pixel.B * Laplacian(index)

index = index + 1

\'防止像素值溢出

If r > 255 Then r = 255

If r < 0 Then r = 0

If g > 255 Then g = 255

If g < 0 Then g = 0

If b > 255 Then b = 255

If b < 0 Then b = 0

\'将指定坐标处的像素设为指定的颜色

NewBitmap.SetPixel(x - 1, y - 1, Color.FromArgb(r, g, b))

Dim pic As WinForm.PictureBox = e.Form.Controls("PictureBox1")

pic.SizeMode = ImageSizeMode.Zoom

pic.Image = NewBitmap

Catch ex As Exception

MessageBox.Show(ex.Message, "提示", MessageBoxButtons.OK, MessageBoxIcon.Error)

Finally

MsgBox("耗时： " & (Date.Now - t).TotalSeconds & " 秒")

End Try

一楼：去灰底效果。附件中更新了图像的3种锐化效果、图像对比度、亮度、饱和度调整代码。

效果如下：

原图片：

此主题相关图片如下：img_20170527_163415.jpg

去灰底后的图片：

此主题相关图片如下：clearbord.jpg

去灰底代码：

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图片锐化代码：1、AForge默认锐化（实际就是拉普拉斯算子锐化）。2、高斯锐化。3、自定义卷积滤镜锐化

并附上：对图片像素的亮度、对比度、饱和度调整代码。

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