Click here to Skip to main content
12,296,779 members (64,145 online)
Rate this:
 
Please Sign up or sign in to vote.
See more: VB8.0 VB VB.NET image
'ofd is open file dialog

Dim img As Bitmap
Dim iscmyk As Boolean
Dim i As String
Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
    ofd.Filter = "Jpg Image(*.jpg)|*.jpg"
    If ofd.ShowDialog = Windows.Forms.DialogResult.OK Then
        img = Bitmap.FromFile(ofd.FileName)
        iscmyk = ((DirectCast(img.Flags, Imaging.ImageFlags) And Imaging.ImageFlags.ColorSpaceCmyk) = Imaging.ImageFlags.ColorSpaceCmyk)
    End If
    img = New Bitmap(img, New Size(120, 190))
    MsgBox("cmyk = " & iscmyk)
    PictureBox1.Image = img
End Sub


i need to check if the image is cmyk or rgb if its cmyk then iscmyk returns true if its not cmyk then iscmyk returns false in my windows 7 pc its returns false for each & every image but in XP it returns perfect answer

why its not working in my other win7 pcs???
Posted 16-Oct-12 19:49pm
Omkaara1.3K

1 solution

Rate this: bad
 
good
Please Sign up or sign in to vote.

Solution 1

here is a low-level (and ugly) workaround. It's designed for JPEG images:

Public Shared Function GetJpegBpp(FileName As String) As Integer
    Dim len As Integer
    Dim fp As FileStream = Nothing
    Dim marker(1) As Byte
    Dim data(15) As Byte
    Dim components As Byte = 0
 
    GetJpegBpp = -2
    Try
        fp = New FileStream(FileName, FileMode.Open, FileAccess.Read)
        GetJpegBpp = -1
        If fp.Read(marker, 0, 2) < 2 OrElse marker(0) <> &HFF OrElse marker(1) <> &HD8 Then Exit Function
        Do
            If fp.Read(marker, 0, 2) < 2 OrElse marker(0) <> &HFF OrElse (marker(1) > 1 And marker(1) < &HC0) Then Exit Function
            If (marker(1) < &HD0 Or marker(1) > &HD9) AndAlso marker(1) > 1 Then
                If fp.Read(data, 0, 2) < 2 Then Exit Function
                len = (CInt(data(0)) << 8) Or data(1)
                len -= 2
                If len < 0 Then Exit Function
                If (marker(1) >= &HC0) And (marker(1) <= &HC3) Then
                    If len < 9 OrElse fp.Read(data, 0, 6) < 6 Then Exit Function
                    components = data(5)
                    If components = 0 OrElse components = 2 OrElse components > 4 OrElse (components * 3 + 6) <> len Then Exit Function
                    len -= 6
                ElseIf marker(1) = &HDA Then
                    If len < (4 + 2 * components) Or (fp.ReadByte() <> components) Then Exit Function
                    len -= 1
                End If
                fp.Position += len
            End If
        Loop Until marker(1) = &HDA Or marker(1) = &HD9
        If components = 0 OrElse marker(1) = &HD9 OrElse (fp.Length - fp.Position) < 3 Then Exit Function
    Catch
        Exit Function
    Finally
        If Not fp Is Nothing Then fp.Close()
    End Try
    GetJpegBpp = components * 8
End Function

You need to replace this line

iscmyk = ((DirectCast(img.Flags, Imaging.ImageFlags) And Imaging.ImageFlags.ColorSpaceCmyk) = Imaging.ImageFlags.ColorSpaceCmyk)

with

iscmyk = (GetJpegBpp(ofd.FileName) = 32)


code is tested & working perfectly
  Permalink  

This content, along with any associated source code and files, is licensed under The Code Project Open License (CPOL)

  Print Answers RSS
Top Experts
Last 24hrsThis month


Advertise | Privacy | Mobile
Web02 | 2.8.160525.2 | Last Updated 2 Nov 2012
Copyright © CodeProject, 1999-2016
All Rights Reserved. Terms of Service
Layout: fixed | fluid

CodeProject, 503-250 Ferrand Drive Toronto Ontario, M3C 3G8 Canada +1 416-849-8900 x 100