Magick++ does not create expected background color

[rich2449]

As far as I can tell from the documentation the following code should produce a black image, with the red pixel in the center.

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	// create image with dimensions of 320x200 pixels, set background color to black	
	Magick::Image image( Magick::Geometry( 320, 200 ), Magick::Color( 0,0,0 ) );

	// set pixel roughly in middle to red
	image.pixelColor( 160, 100, Magick::Color( "red" ) );

	// write out as png image
	image.write( "test.png" );

However the image produced has a light grey background color, RGB(205,205,205).

I'm sure I'm missing something here.... but why is the background not black, as specified in the constructor to the image object?

Thanks in advance, Rich

[fmw42]

try setting the background color

[rich2449]

Setting the background color via

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image.backgroundColor( Magick::Color( 0,0,0 ) );

makes no difference, the background still comes out being 205,205,205?

[fmw42]

I don't use APIs, only command line, but this topic might help --- see viewtopic.php?f=6&t=15832#p56657

[rich2449]

Ah ha! Thank you for the link.

It would seem that the image constructor does not set the background color, what color it does set I have no idea. The documentation just states "Construct a blank image canvas of specified size and color". Can anyone shed any light on what "color" is set with this constructor?

Adding the lines:

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	image.backgroundColor( Magick::Color( 0,0,0 ) );
	MagickCore::SetImageBackgroundColor( image.image() );

created the desired black background. Thanks to all for helping.