Convert color bmp always to White & Black not to B&W

[Konrad B]

I found out, that the filter setting "-blur 0x1" dont works with IM 6.8.9-9

With this code:

Code: Select all

convert 20701-2757.bmp -colorspace gray -auto-level -threshold 50% -level 0x50% result.bmp

(without filter "-blur 0x1") the bmp file (result.bmp) was created - but the background was black.
http://bogx.de/media/result.bmp
I need background white and foreground black (= invert of the result above).

[snibgo]

I think Konrad B wants a binary output, with black and white only. If so, then antiliasing isn't needed, so "-blur" isn't needed.

I need background white and foreground black (= invert of the result above).

Then put "-negate" before the final output filename.

[Konrad B]

Thanks guys!

I have the solution for PHP environment especially for my problem (to have always white background in 1-bit images) - is very simple:

Code: Select all

exec("convert input.png -monochrome -colors 2 result.bmp");
$color=exec('convert result.bmp -format "%[pixel: u.p{0,0}]" info:');
if ($color == 'black') {
 exec("convert result.bmp -negate result.bmp");	
}

Best regards,
Konrad

[snibgo]

How do you define "background"?

You have decided that the pixel at (0,0) is always background. Fine.

[Konrad B]

You have decided that the pixel at (0,0) is always background. Fine.

yes - exactly - all images have solid backgrounds in this project and are therefore very simple bitmaps

Best regards,
Konrad

[fmw42]

convert 20701-2756.bmp -colorspace gray -auto-level -threshold 50% -blur 0x1 -level 0x50% result_2.bmp

Result:
line 2 dont works - no file (result_2.bmp) is created

It works fine for me on IM 6.9.7.10 Q16 Mac OSX.

What do you mean by:

no file (result_2.bmp) is created