The following code example demonstrates how to construct a new Bitmap from a file, using the GetPixel and SetPixel methods to recolor the image. It also uses the PixelFormat, Width, and Height properties.
This example is designed to be used with a Windows Forms that contains a Label, PictureBox, and Button named Label1, PictureBox1, and Button1, respectively. Paste the code into the form and associate the Button1_Click method with the button's Click event.
Visual Basic Copy Code
Dim image1 As Bitmap
Private Sub Button1_Click(ByVal sender As System.Object, _
ByVal e As System.EventArgs) Handles Button1.Click
Try
' Retrieve the image.
image1 = New Bitmap( _
"C:\Documents and Settings\All Users\Documents\My Music\music.bmp", _
True)
Dim x, y As Integer
' Loop through the images pixels to reset color.
For x = 0 To image1.Width - 1
For y = 0 To image1.Height - 1
Dim pixelColor As Color = image1.GetPixel(x, y)
Dim newColor As Color = _
Color.FromArgb(pixelColor.R, 0, 0)
image1.SetPixel(x, y, newColor)
Next
Next
' Set the PictureBox to display the image.
PictureBox1.Image = image1
' Display the pixel format in Label1.
Label1.Text = "Pixel format: " + image1.PixelFormat.ToString()
Catch ex As ArgumentException
MessageBox.Show("There was an error." _
& "Check the path to the image file.")
End Try
End Sub |