ImageMagick，用不透明的白色代替半透明白色 [英] ImageMagick, replace semi-transparent white with opaque white

问题描述

我有一个带有完全透明背景和半透明白色前景的图标。我想让前景完全不透明，这可以通过ImageMagick实现吗？

I have an icon with a fully transparent background and a semi-transparent, white foreground. I would like to make the foreground fully opaque, can this be achieved with ImageMagick?

我试过玩杂耍的不同组合;

I have tried juggling different combinations of these;

http://www.imagemagick.org/discourse -server / viewtopic.php？t = 12619

http://www.imagemagick.org/discourse-server/viewtopic.php?t=18196

http://www.imagemagick.org/discourse-server/viewtopic .php？t = 16718

，但无法产生预期的结果。任何提示？

, but cannot produce the desired result. Any tips?

推荐答案

如果你发布了你的图标会更容易，但我的测试显示这适用于我认为你拥有：

It would be easier if you posted your icon, but my testing shows that this works for what I think you have:

convert icon.png -channel A -threshold 75% output.png

上面有些粗糙，因为它使所有部分透明像素完全不透明。如果你想要更多手术，当红色，绿色和蓝色像素大于90％且原始不透明度（alpha）在40％之间时，你只能将不透明度设置为完全不透明-60％喜欢这个：

The above is somewhat coarse as it makes all partially transparent pixels fully opaque. If you wanted to be a bit more surgical, you could only set the opacity to fully opaque when the Red, Green and Blue pixels are greater than 90% and the original opacity (alpha) is between 40%-60% like this:

convert icon.png -channel A \
   -fx "(r>0.9 && g>0.9 && b>0.9 && a>0.4 && a<0.6) ? 1.0 : a" output.png

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