我如何改变颜色：
进入这个：
我使用Gimp生成输出图像,输入图像为第一层,图像背景颜色为第二层,在“图层”面板中我选择了“颜色”模式
我想保留背景颜色,但希望颜色为棕色.
有任何想法与ChunkyPNG这样做？或者我应该使用带有颜色查找表的ImageMagick？
解决方法
谢谢你的想法.
我发现Linuxios中最有用的一个Gimp layer modes
require "json"
require "httpclient"
require "chunky_png"
module ChunkyPNG::Color
def h(value)
r,g,b = r(value).to_f / MAX,g(value).to_f / MAX,b(value).to_f / MAX
min,max = [r,b].minmax
return 0 if max == min
result = case max
when r then (g - b) / (max - min) + (g < b ? 6 : 0)
when g then (b - r) / (max - min) + 2
when b then (r - g) / (max - min) + 4
end
result * 60
end
def s(value)
min,max = [r(value),g(value),b(value)].minmax.map { |value| value.to_f / MAX }
max == 0 ? 0 : (max - min) / max
end
def v(value)
[r(value),b(value)].max.to_f / MAX
end
def hsv(h,s,v)
h = h.to_f / 360
i = (h * 6).floor
f = h * 6 - i
p = v * (1 - s)
q = v * (1 - f * s)
t = v * (1 - (1 - f) * s)
case i % 6
when 0 then r,b = v,t,p
when 1 then r,b = q,v,p
when 2 then r,b = p,t
when 3 then r,q,v
when 4 then r,b = t,p,v
when 5 then r,q
end
rgb *[r,b].map {|value| (value * 255).round }
end
end
module CoderWall
module_function
def badges(username)
url = URI.escape("https://coderwall.com/#{username}.json")
response = HTTPClient.get(url)
json = JSON.parse(response.body)
urls = json['badges'].map {|b| b['badge']}
brown = ChunkyPNG::Color.from_hex("#bf8a30")
hue = ChunkyPNG::Color.h(brown)
saturation = ChunkyPNG::Color.s(brown)
value = ChunkyPNG::Color.v(brown)
urls.each do |url|
matches = url.match /(\w+)\-/
response = HTTPClient.get(url)
filename = "./tmp/coderwall/"+matches[1]+".png"
File.open(filename,"w") {|f| f.write(response.body)}
image = ChunkyPNG::Image.from_file(filename)
image.pixels.map! do |pixel|
v = ChunkyPNG::Color.v(pixel)
unless ChunkyPNG::Color.a(pixel) > 0
v = value
end
ChunkyPNG::Color.hsv(hue,saturation,v)
end
image.save(filename.gsub(/\.png/,"_brown.png"),:fast_rgba)
end
end
end
badges = CoderWall.badges("astropanic")
上面的代码包含在网络上找到的一些片段.