Sha256: ca3d1d378260f0a74d35afd8ad8fce5035dfbbd0f8cee2e443c8113852bf7201
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Size: 1.48 KB
Versions: 18
Compression:
Stored size: 1.48 KB
Contents
require 'set'
module ZSteg
class Masker
def initialize image, params = {}
@src = image.is_a?(ZPNG::Image) ? image : ZPNG::Image.load(image)
@masks = params[:masks] || {}
@mask = params[:mask] || @masks[:all]
@normalize = params[:normalize]
[:r, :g, :b, :a].each{ |x| @masks[x] ||= @mask }
end
def mask params = {}
dst = ZPNG::Image.new :width => @src.width, :height => @src.height
rm, gm, bm, am = @masks[:r], @masks[:g], @masks[:b], @masks[:a]
rd, gd, bd, ad = rm==0?1:rm, gm==0?1:gm, bm==0?1:bm, am==0?1:am
# duplicate loops for performance reason
if @normalize
if rm == 0 && gm == 0 && bm == 0 && am != 0
# alpha2grayscale
@src.each_pixel do |c,x,y|
c.r = c.g = c.b = (c.a & am) * 255 / ad
c.a = 0xff
dst[x,y] = c
end
else
# normal operation
@src.each_pixel do |c,x,y|
#TODO: c.to_depth(8)
# further possible optimizations:
# a) precalculate (255 / Xm)
c.r = (c.r & rm) * 255 / rd
c.g = (c.g & gm) * 255 / gd
c.b = (c.b & bm) * 255 / bd
c.a = (c.a & am) * 255 / ad
dst[x,y] = c
end
end
else
@src.each_pixel do |c,x,y|
#TODO: c.to_depth(8)
c.r &= rm
c.g &= gm
c.b &= bm
c.a &= am
dst[x,y] = c
end
end
dst
end
end
end
Version data entries
18 entries across 18 versions & 1 rubygems