Breadcrumbs

[skyteam]

Hi guys how would I would I go about this I want to change from colored to white and black hehaho;

[Dummy1912]

hello sky

this will do the job

i hope you mean grayscale?

Code: Select all

Public Function grayscale(ByVal img As Image) As Boolean
        Dim cm As New System.Drawing.Imaging.ColorMatrix(New Single()() _
                               {New Single() {0.299, 0.299, 0.299, 0, 0}, _
                                New Single() {0.587, 0.587, 0.587, 0, 0}, _
                                New Single() {0.114, 0.114, 0.114, 0, 0}, _
                                New Single() {0, 0, 0, 1, 0}, _
                                New Single() {0, 0, 0, 0, 1}})
        Return drawImage(img, cm)
    End Function

use it like this:

Code: Select all

grayscale(PictureBox1.Image)
        PictureBox1.Invalidate()

Dummy1912

[Dummy1912]

try this black and white

Code: Select all

Imports System.Drawing
 Imports System.Drawing.Imaging
 Dim bitmap As Bitmap
 bitmap = New Bitmap( Me.Picture1.Image)
 Dim x, y
 Dim d As Byte
 For x = 0 To Me.Picture.Image.Width - 1
 For y = 0 To Me.Picture.Image.Height - 1
 d = Math.Round((bitmap.GetPixel(x, y).R * 0.299 + bitmap.GetPixel(x, y).G * 0.587 + bitmap.GetPixel(x, y).B * 0.114))
 bitmap.SetPixel(x, y, Color.FromArgb(d, d, d))
 Next y
 Next x
 Me.Picture1.Image = bitmap

[skyteam]

hey i get an error on drawimage(img, cm) 'drawimage' is not declared. It may be inaccessible due to its protection level.

tryed to declare it and still gives me error

[Dummy1912]

did you import this

Imports System.Drawing
Imports System.Drawing.Imaging

[skyteam]

Nvm thanks got it to work

[Dummy1912]

hmmm

is drawimage a picturebox?
so you need to do:

Code: Select all

drawimage.image = openfiledialog1.filename

but it must work

[MrAksel]

Code: Select all

Public Sub BlackWhite(ByVal img As Bitmap)
   Dim bmd As BitmapData = img.LockBits(New Rectangle(Point.Empty, img.Size), ImageLockMode.ReadWrite, PixelFormat.Format24bppRgb)
   Dim data(0 To bmd.Stride * bmd.Height) As Byte
   Marshal.Copy(bmd.Scan0, data, 0, data.Length)

   Dim r, g, b As Byte

   For y = 0 To img.Height
      For x = 0 To img.Width
          b = data(y * bmd.Stride + x * 3)
          g = data(y * bmd.Stride + x * 3 + 1)
          r = data(y * bmd.Stride + x * 3 + 2)

          If b + g + r > 381 Then
             data(y * bmd.Stride + x * 3) = 255
             data(y * bmd.Stride + x * 3 + 1) = 255
             data(y * bmd.Stride + x * 3 + 2) = 255
          Else
             data(y * bmd.Stride + x * 3) = 0
             data(y * bmd.Stride + x * 3 + 1) = 0
             data(y * bmd.Stride + x * 3 + 2) = 0
          End If
      Next
   Next

   Marshal.Copy(data, bmd.Scan0, 0, data.Length)
   img.UnlockBits(bmd)
End Sub

I guess that will work
EDIT!!
I made an awful mistake, I swapped height and width. Now it will work

[skyteam]

Yup it works but its it turns red into gray and my OCR cant recognize it I would need the black to turn to white and the red to turn to white and the white to turn to black since some text is white oh and green to white to

[MrAksel]

You can change the value 381 to something lower if you want more to turn white. Or make it higher if more is to turend black.