Cut image parts

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  14 years ago

  by lexian

  Alexis Méndez

  , Puerto Rico

  Joined 14 years ago

  Hi,

   

  How can I cut just some parts in an image? If somebody here know please.

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  14 years ago

  by TwoFaced

  Thomas Reynard

  , United States

  Joined 15 years ago

  Here is a start.  This code simply takes a small piece of an image.  I'm not exactly sure what your requirements are and my knowledge here is limited so I don't know if I'll be much help.

      Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
          'A rectangle that describes the area we want from our source image
          'In this I created a 30x30 square that begins at the top left
          Dim rec As New Rectangle(0, 0, 30, 30)
          'A bitmap object sized to match the size of our desired cutout
          'This image will hold our cut-out peace
          Dim bmp As New Bitmap(rec.Width, rec.Height)
          'A graphics object to draw the cut-out onto our bitmap object (bmp)
          Dim gr As Graphics = Graphics.FromImage(bmp)
  
          'I passed our source image (the image of PictureBox1) and the rectangle/piece I wanted
          gr.DrawImageUnscaledAndClipped(PictureBox1.Image, rec)
  
          'Cleanup
          gr.Dispose()
  
          'Display the piece in PictureBox2
          PictureBox2.Image = bmp
      End Sub

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  14 years ago

  by TwoFaced

  Thomas Reynard

  , United States

  Joined 15 years ago
  Okay, somehow I got back to playing around with cropping images.  I'd ignore the code I posted earlier.  It appears to work but doesn't really.  I realized it didn't work while working on the new code below.  All you need is a form with a picturebox named pbDraw.  Load an image into the picture box and make sure the sizemode is set to normal or AutoSize.  This is a must for the image cropping to work correctly.  Paste this code into your project and test it out.  I've commented it so you should be able to understand it.  The code was inspired by code that Nimpo had posted in this thread: http://www.developerfusion.co.uk/forums/thread/110179/.  I bookmarked it a while ago and decided to check it out.  It was a great help even though it didn't work perfectly for me.  I also learned how to successfully take a peace of an image from this web page: http://abstractvb.com/code.asp?A=1088  I'm not sure if it will help you but I want to give credit where credit is due.  Well enough talk, here is the code.  Hope it helps.

  'This is an example that allows a user to select a portion
  'of an image using a rectangular selection and crop that area
  Public Class Form1
      'The pen we'll use to draw our selection rectangle
      Dim PenDashed As New Pen(Color.White)
      'Drawing flag (If True draw selection rectangle)
      Dim Drawing As Boolean = False
      'Location mouse button was initially pressed
      Dim DrawStart As Point
      'Our selection rectangle
      Dim DrawRect As Rectangle
  
      Private Sub Form1_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load
          'Use a dashed style
          PenDashed.DashStyle = Drawing2D.DashStyle.Dash
      End Sub
  
      Private Sub pbDraw_MouseDown(ByVal sender As Object, ByVal e As System.Windows.Forms.MouseEventArgs) Handles pbDraw.MouseDown
          'Allow drawing of selection rectangle if user pressed left mouse button
          If e.Button = Windows.Forms.MouseButtons.Left Then
              Drawing = True
              'Make note of our start location
              DrawStart = e.Location
          End If
      End Sub
  
      Private Sub pbDraw_MouseMove(ByVal sender As Object, ByVal e As System.Windows.Forms.MouseEventArgs) Handles pbDraw.MouseMove
          'If we are not drawing then return
          If Not Drawing Then Return
  
          'clear the previous selection rectangle
          If DrawRect <> Nothing Then
              DrawRect.Inflate(1, 1)
              pbDraw.Invalidate(DrawRect)
              pbDraw.Update()
          End If
  
          'Current mouse location
          Dim newLocation As Point = e.Location
  
          'Adjust the X location if it's outside pbDraw's bounds
          If newLocation.X < 0 Then
              newLocation.X = 0
          ElseIf newLocation.X > pbDraw.ClientSize.Width Then
              newLocation.X = pbDraw.ClientSize.Width
          End If
  
          'Adjust the Y location if it's outside pbDraw's bounds
          If newLocation.Y > pbDraw.ClientSize.Height Then
              newLocation.Y = pbDraw.ClientSize.Height
          ElseIf newLocation.Y < 0 Then
              newLocation.Y = 0
          End If
  
          'Get a new rectangle for our selection
          DrawRect = GetRectangle(DrawStart, newLocation)
  
          'Draw a selection rectangle
          pbDraw.CreateGraphics.DrawRectangle(PenDashed, DrawRect)
      End Sub
  
      Private Sub pbDraw_MouseUp(ByVal sender As Object, ByVal e As System.Windows.Forms.MouseEventArgs) Handles pbDraw.MouseUp
          'Crop image if left mouse button was released.
          'Cropping the image immediatly is probably a bad idea
          'but that behavior could easily be changed.
          If e.Button = Windows.Forms.MouseButtons.Left Then
              Drawing = False
              CropImage()
          End If
      End Sub
  
      'Returns a rectangle defined by two points
      Private Function GetRectangle(ByVal point1 As Point, ByVal point2 As Point) As Rectangle
          Dim Left, Right, Top, Bottom As Integer
  
          If point1.X < point2.X Then
              Left = point1.X
              Right = point2.X
          Else
              Left = point2.X
              Right = point1.X
          End If
  
          If point1.Y < point2.Y Then
              Top = point1.Y
              Bottom = point2.Y
          Else
              Top = point2.Y
              Bottom = point1.Y
          End If
  
          Return Rectangle.FromLTRB(Left, Top, Right, Bottom)
      End Function
  
      'Crops the image defined by DrawRect
      Private Sub CropImage()
          'Return if no selection has been made
          If DrawRect = Nothing Then Return
          'A new image to hold our cropped region
          Dim bmp As New Bitmap(DrawRect.Width, DrawRect.Height)
          'Graphics object
          Dim gr As Graphics = Graphics.FromImage(bmp)
          'Draw the defined region onto our new image
          gr.DrawImage(pbDraw.Image, 0, 0, DrawRect, GraphicsUnit.Pixel)
  
          pbDraw.Image = bmp
      End Sub
  
  End Class

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• • Reply

  14 years ago

  by lexian

  Alexis Méndez

  , Puerto Rico

  Joined 14 years ago
  Thanks. It helps.
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