How to Convert bitmap to black/white?

[Peanutman]

I have a bitmap loaded into memory by using the following code:

Data = Clipboard.GetDataObject()
If Data.GetDataPresent(GetType(System.Drawing.Bitmap)) Then
    bmap = CType(Data.GetData(GetType(System.Drawing.Bitmap)), Image)
    Dim g As Graphics = Graphics.FromImage(bmap)
Endif

I would like to convert this bitmap in memory to a monochrome bitmap (black/white) and display it in a picbox.
The problem is i have no idea how to do this. Do i have to it pixel by pixel? or is there some cool VB.Net funtion to convert it to black/white.

Can anyone put me on the correct path pls.
Reinout,

 

[kulrom]

Ok, try this and let me know if you are satisfied from.

Play around with the ColorMatrix values ... Cheers

 

[Peanutman]

Cool! Thank you extremely much.
The invert/grayscale subs work great.

I just have one question though. I understand the picture is displayed with that colormatrix applied to it. But what do the numbers in that matrix represent? That I don't fully understand.

And would be possible to convert the pic to full black-white (no grayscale, just black&white) by editing the matrix somehow?

Thanks extremely much, you have already helpen me a bunch.

Reinout,

 

[kulrom]

Ok, as i haven't time to experiment with that i will give you a clue and i hope you'll find some logic.
Well, heres a clue - 1st split the image into Intensity, Saturation and Hue.
Then find an optimal line through the 3D table to convert lively color into boring grey and that's it.

Cheers

 

[kulrom]

How to convert color image file to black and white

How about this? Take a look at the attached project ... Cheers

 

[Peanutman]

waw, thanks a lot.
It's exactly what i wanted, and even more
Thanks for the ubercustomizeable code

Reinout,

 

[mostafazare]

Hi guys
It is great.
Is this possible to omit an exact color by this matrix?