How to crop an image in vb.net? - vb.net

Question

The image can be anything. It can be jpg, png, anything.
Load it.
Crop it. Say removing first 100 pixels from the left.
Save to the same file

Answer 1

Use Graphics.DrawImage Method (Image, RectangleF, RectangleF, GraphicsUnit) method.
Dim fileName = "C:\file.jpg"
Dim CropRect As New Rectangle(100, 0, 100, 100)
Dim OriginalImage = Image.FromFile(fileName)
Dim CropImage = New Bitmap(CropRect.Width, CropRect.Height)
Using grp = Graphics.FromImage(CropImage)
grp.DrawImage(OriginalImage, New Rectangle(0, 0, CropRect.Width, CropRect.Height), CropRect, GraphicsUnit.Pixel)
OriginalImage.Dispose()
CropImage.Save(fileName)
End Using

Answer 2

Ref: Graphics.DrawImage and Image Cropping with Image Resizing Using VB.NET
private void btnCropImage_Click(object sender, EventArgs e)
{
OpenFileDialog dlg = new OpenFileDialog();
dlg.ShowDialog();
//check your filename or set constraint on fileopen dialog
//to open image files
string str = dlg.FileName;
//Load Image File to Image Class Object to make crop operation
Image img = System.Drawing.Bitmap.FromFile(str);
// Create rectangle for source image, what ever it's size.
GraphicsUnit units = GraphicsUnit.Pixel;
RectangleF srcRect = img.GetBounds(ref units);
// Create rectangle for displaying image - leaving 100 pixels from left saving image size.
RectangleF destRect = new RectangleF(100.0F, 0.0F, srcRect.Width - 100, srcRect.Height);
// Bitmap class object to which saves croped image
Bitmap bmp = new Bitmap((int)srcRect.Width - 100, (int)srcRect.Height);
// Draw image to screen.
Graphics grp = Graphics.FromImage(bmp);
grp.DrawImage(img, destRect, srcRect, units);
//save image to disk
bmp.Save("e:\\img.jpeg", System.Drawing.Imaging.ImageFormat.Jpeg);
//Clear memory for Unused Source Image
img.Dispose();
}
Hope this help you..

Answer 3

Region "Image Cropping"
Dim cropX As Integer
Dim cropY As Integer
Dim cropWidth As Integer
Dim cropHeight As Integer
Dim oCropX As Integer
Dim oCropY As Integer
Dim cropBitmap As Bitmap
Public cropPen As Pen
Public cropPenSize As Integer = 1 '2
Public cropDashStyle As Drawing2D.DashStyle = Drawing2D.DashStyle.Solid
Public cropPenColor As Color = Color.Yellow
Private Sub RotateBtn_Click(sender As System.Object, e As EventArgs) Handles RotateBtn.Click
' RotateImage(PreviewPictureBox.Image, offset:=, angle:=90)
crobPictureBox.Image.RotateFlip(RotateFlipType.Rotate270FlipNone)
'PreviewPictureBox.Image.RotateFlip(RotateFlipType.Rotate270FlipNone)
'(45, PreviewPictureBox.Image)
End Sub
Private Sub crobPictureBox_MouseDown(ByVal sender As System.Object, ByVal e As System.Windows.Forms.MouseEventArgs) Handles crobPictureBox.MouseDown
Try
If e.Button = Windows.Forms.MouseButtons.Left Then
cropX = e.X
cropY = e.Y
cropPen = New Pen(cropPenColor, cropPenSize)
cropPen.DashStyle = DashStyle.DashDotDot
Cursor = Cursors.Cross
End If
crobPictureBox.Refresh()
Catch exc As Exception
End Try
End Sub
Dim tmppoint As Point
Private Sub crobPictureBox_MouseMove(ByVal sender As Object, ByVal e As System.Windows.Forms.MouseEventArgs) Handles crobPictureBox.MouseMove
Try
If crobPictureBox.Image Is Nothing Then Exit Sub
If e.Button = Windows.Forms.MouseButtons.Left Then
crobPictureBox.Refresh()
cropWidth = e.X - cropX
cropHeight = e.Y - cropY
crobPictureBox.CreateGraphics.DrawRectangle(cropPen, cropX, cropY, cropWidth, cropHeight)
End If
' GC.Collect()
Catch exc As Exception
If Err.Number = 5 Then Exit Sub
End Try
End Sub
Private Sub crobPictureBox_MouseUp(ByVal sender As Object, ByVal e As System.Windows.Forms.MouseEventArgs) Handles crobPictureBox.MouseUp
Try
Cursor = Cursors.Default
Try
If cropWidth < 1 Then
Exit Sub
End If
Dim rect As Rectangle = New Rectangle(cropX, cropY, cropWidth, cropHeight)
Dim bit As Bitmap = New Bitmap(crobPictureBox.Image, crobPictureBox.Width, crobPictureBox.Height)
cropBitmap = New Bitmap(cropWidth, cropHeight)
Dim g As Graphics = Graphics.FromImage(cropBitmap)
g.InterpolationMode = Drawing2D.InterpolationMode.HighQualityBicubic
g.PixelOffsetMode = Drawing2D.PixelOffsetMode.HighQuality
g.CompositingQuality = Drawing2D.CompositingQuality.HighQuality
g.DrawImage(bit, 0, 0, rect, GraphicsUnit.Pixel)
' g.DrawImage(bit, 0, 0, rect,GraphicsUnit.Pixel)
PreviewPictureBox.Image = cropBitmap
Catch exc As Exception
End Try
Catch exc As Exception
End Try
End Sub