Replace ANY colour Except #ffffff with #000000

[Rye]

So I have this picture:




And want to repace all colours EXCEPT #ffffff with #A7A7AF

I hope this can be done "pixle perfect".

Thanks in advance.

[fmw42]

Unfortunately, your image has no pure white #ffffff

If it did, then

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convert "Snow_Sharo 001.gif" -fill "#A7A7AF" +opaque "#ffffff" result.gif

If you want to use a fuzz value to catch the close to white values then try

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convert "Snow_Sharo 001.gif" -fuzz 5% -fill "#A7A7AF" +opaque "#ffffff" result.gif

Adjust the fuzz value as desired

[Rye]

the second command seems to do nothing to my picture (I replaced "show:" with result.gif).

Am I doing something wrong ?

I also played around with the fuzz value as instructed, however the change was still - nothing...


This command *did* something, however still not as good as I wished it to be:

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convert "001.gif" -fill white +opaque #A7A7AF -transparent white result.gif

[fmw42]

Sorry, I forgot to replace show: with a filename. Edited now to fix that.

If you are on Windows replace % with %%.

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convert "Snow_Sharo 001.gif" -fuzz 5%% -fill "#A7A7AF" +opaque "#ffffff" result.gif

Note the double quotes about your file name, since it has spaces in it. I am not sure how Windows handles that.

see http://www.imagemagick.org/Usage/windows/

Note again, that the image you provide has not perfectly white pixels.

[Rye]

using a second % doesn't help.

How can I find the version etc. ?

[fmw42]

Post your exact command and the input image.

To get the IM version,

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convert -version

[Rye]

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convert 001.gif -fuzz 5%% -fill "#A7A7AF" +opaque "#ffffff" 002.gif

This does nothing to the image posted above (have you found a satisfactionary code that works with the above image ?)


IMGMagick version:
Version: ImageMagick 6.8.3-4 2013-02-20 Q16 http://www.imagemagick.org
Copyright: Copyright (C) 1999-2013 ImageMagick Studio LLC
Features: DPC OpenMP
Delegates: bzlib fontconfig freetype jng jp2 jpeg lcms lzma pango png ps tiff x xml zlib

[fmw42]

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convert 001.gif -fuzz 5%% -fill "#A7A7AF" +opaque "#ffffff" 002.gif

This does nothing to the image posted above (have you found a satisfactionary code that works with the above image ?)

It has converted your background from #A8A8B0 to #A7A7AF. But there is little (visual) difference in that color change.

try

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convert 001.gif -fuzz 5%% -fill "#FF0000" +opaque "#ffffff" 002.gif

and you will see that your background is now red

[Rye]

Is it possible to define multiple colors that are to be exluded from the replace ?

If I would like to replace any colour except for these three: #F4F4FC #F7F7FF #F9F9FF with let's say #000000.

How'd I do it ?

[fmw42]

As long as your image has no (partial or fully) transparent pixels, then do the following


Unix:

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convert yourimage \
-fill none -opaque "#F4F4FC" \
-fill none -opaque "#F7F7FF" \
-fill none -opaque "#F9F9FF" \
\( -clone 0 -fill "#000000" -colorize 100  \) \
+swap -compose over -composite resultimage

Windows:

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convert yourimage ^
-fill none -opaque "#F4F4FC" ^
-fill none -opaque "#F7F7FF" ^
-fill none -opaque "#F9F9FF" ^
( -clone 0 -fill  "#000000" -colorize 100 ) ^
+swap -compose over -composite resultimage

Add -fuzz if so desired to get close colors.

[Rye]

This outputs:
"convert.exe: invalid argument for option '-colorize': #000000 @ error/convert.c/ConvertImageCommand/969."

[snibgo]

I think Fred made a typo and meant "-colorize 100" (no quotes needed).

The following Windows BAT script makes a sample file. From this, it makes all colours except the specified colours into purple. Change "purple" to anything you want.

There may be a simpler method.

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convert ^
  -size 20x20 ^
  xc:red xc:lime xc:blue xc:#F4F4FC xc:#F7F7FF xc:#F9F9FF xc:khaki ^
  +append ^
  sample.png

convert ^
  sample.png ^
  ( -clone 0 -fill Purple -colorize 100 ) ^
  +swap ^
  -alpha set ^
  ( -clone 1 ^
    ( -clone 0 +transparent #F4F4FC ) ^
    ( -clone 0 +transparent #F7F7FF ) ^
    ( -clone 0 +transparent #F9F9FF ) ^
    -delete 0 ^
    -evaluate set 0 ^
    -layers flatten ^
    -negate ^
  ) ^
  -compose Over -composite ^
  s1.png

convert ^
  s1.png -unique-colors txt:

The final "-unique-colors" is to verify the result.

[fmw42]

I think Fred made a typo and meant "-colorize 100" (no quotes needed).

Yes, indeed I made a mistake. Thanks for catching it snibgo. I have fixed my command above.

[Rye]

Ok, perfect, now it works

BTW: colorize seems to only "tone" the color down.

Is there a way to make it pitch black (for example) just by once executing this ?

[fmw42]

use

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-fill black -colorize 100

The 100 means totally change to that exact color. Alternately, you can use

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-evaluate set 0

In place of the above. That will make any image totally black. There are lots of ways to do this.

see
http://www.imagemagick.org/Usage/canvas/#solid
and especially
http://www.imagemagick.org/Usage/canvas/#other