Create or Save Image as Black and White

[Xombie]

In the past I've used...

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TestImage = CreateImage(#PB_Any, 2550, 4200, 1)
hdc = CreateCompatibleDC_(0)
SelectObject_(hdc, ImageID(TestImage))
SetDIBColorTable_(hdc, 0, 2, @palette())
DeleteDC_(hdc) : hdc = 0

...to create a black and white image and it's worked fine. What's the recommended method for PB 4.50?

[Thorium]

4.50 does not support indexed images any longer.
But it supports to save them, so i think the solution is to just use 24bit image and just use black and white, when you save it, you specify it as 1bit.

[Xombie]

I'm using GDI+ to save the image (multipage TIF) so I'll dig around on that to see how to save it as bitonal.

Thanks!

[srod]

You can use api to create a monochrome dibsection easily enough...

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hdc = CreateCompatibleDC_(0)
If hdc
  With bmi.BITMAPINFO
    \bmiHeader\biSize = SizeOf(BITMAPINFOHEADER) 
    \bmiHeader\biWidth = 300
    \bmiHeader\biHeight   = 300
    \bmiHeader\biPlanes   = 1 
    \bmiHeader\biBitCount = 1
  EndWith 
  hBMP = CreateDIBSection_(hdc, @bmi, #DIB_RGB_COLORS, 0, 0, 0) 
  If hBMP
    oldimage = SelectObject_(hdc, hBMP)
    Dim colors.l(1)
      colors(0) = #Black
      colors(1) = #White 
    SetDIBColorTable_(hdc, 0, 2, @Colors())
    SelectObject_(hdc, oldimage)
  EndIf
  DeleteDC_(hdc)
EndIf

hBMP gives you an image handle which you can use in image gadgets etc.

Alternatively use CreateBitmap_() to create a monochrome ddb. This of course will have no color table.

[Fred]

You can specify the 'Depth' in SaveImage() in 4.50, it should do the trick (don't use dithering if you only use 2 colors in your 24 bit image).

[Xombie]

And for GDI+ I simply did the following...

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EncoderParameters\Count = 2
;
CopyMemory(?EncoderSaveFlag, @EncoderParameters\Parameter[0]\Guid, SizeOf(GUID))
EncoderParameters\Parameter[0]\type = 4
EncoderParameters\Parameter[0]\NumberOfValues = 1
EncoderParameters\Parameter[0]\Value = @ParameterValue
;
ColorDepth = 1
;
CopyMemory(?EncoderColorDepth, @EncoderParameters\Parameter[1]\Guid, SizeOf(GUID))
EncoderParameters\Parameter[1]\type = 4
EncoderParameters\Parameter[1]\NumberOfValues = 1
EncoderParameters\Parameter[1]\Value = @ColorDepth

Where EncoderColorDepth is...

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EncoderColorDepth:
  Data.l $66087055
  Data.w $AD66, $4C7C
  Data.b $9A, $18, $38, $A2, $31, $0B, $83, $37