Some questions regarding image manipulation (.net -> QT)

[freitag]

Hio, i just started with QT and I want to port some of my stuff from win to mac.

But currently I'm a bit stuck at this point:

I use lockbits in vb.net to get the most speed to manipulate images (as far as I know this should be the fastest way in vb.net). This is a small example how to invert an image

Public Shared Function Invert_Image(ByVal doImage As Bitmap) As Bitmap
 
        Dim imageData As BitmapData = doImage.LockBits(New Rectangle(0, 0, doImage.Width, doImage.Height), _
        System.Drawing.Imaging.ImageLockMode.ReadWrite, PixelFormat.Format32bppArgb)
 
        Dim pointer0 As IntPtr = imageData.Scan0
        Dim stride As Integer = imageData.Stride
 
        Dim pixels(doImage.Width * doImage.Height - 1) As Integer
 
        Copy(pointer0, pixels, 0, pixels.Length)
 
        For i As Integer = 0 To pixels.Length - 1
            pixels(i) = (Not pixels(i) And &HFFFFFF) Or (pixels(i) And &HFF000000)
        Next i
 
        Copy(pixels, 0, pointer0, pixels.Length)
 
        doImage.UnlockBits(imageData)
 
        Return doImage
    End Function

Public Shared Function Invert_Image(ByVal doImage As Bitmap) As Bitmap

        Dim imageData As BitmapData = doImage.LockBits(New Rectangle(0, 0, doImage.Width, doImage.Height), _
        System.Drawing.Imaging.ImageLockMode.ReadWrite, PixelFormat.Format32bppArgb)

        Dim pointer0 As IntPtr = imageData.Scan0
        Dim stride As Integer = imageData.Stride

        Dim pixels(doImage.Width * doImage.Height - 1) As Integer

        Copy(pointer0, pixels, 0, pixels.Length)

        For i As Integer = 0 To pixels.Length - 1
            pixels(i) = (Not pixels(i) And &HFFFFFF) Or (pixels(i) And &HFF000000)
        Next i

        Copy(pixels, 0, pointer0, pixels.Length)

        doImage.UnlockBits(imageData)

        Return doImage
    End Function

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And this is the point where my questions starts...is there a similar way to manipulate images in QT?
I've read the documentation for QImage but I still don't understand wether QImage got something like this lockbits or wether QT got maybe some even faster methode.

Would some one clarify this to me maybe with some small example?

Thx in advance
freitag