画像フィルターアルゴリズムコードのRuby実装

 #Grayscale the image
 #Take the average of the three RGB colors
 def self.grey(bmp)
  for i in 0 ... bmp.height - 1
   for j in 0 ... bmp.width - 1
    rgb = bmp.getRGB(i, j)
    grey = rgb.r.to_f * 0.3 + rgb.g.to_f * 0.59 + rgb.b.to_f * 0.11.to_i
    bmp.setRGB(i, j, RGB.new(grey, grey, grey))
   end
  end
 end

#Binarize images
 # less than a certain threshold set to 0 0 0, greater than set to 255 255 255
 def self.binarization(bmp)
  imageGreyLevel = bmp.getGreyLevel
  for i in 0 ... bmp.height - 1
   for j in 0 ... bmp.width - 1
    rgb = bmp.getRGB(i, j)
    if rgb.getGreyLevel<imageGreyLevel
     bmp.setRGB(i, j, RGB.new(0, 0, 0))
    else
     bmp.setRGB(i, j, RGB.new(255, 255, 255))
    end
   end

  end
 end

#negative image
 #RGB takes the inverse color 255-
 def self.contraryColor(bmp)
  for i in 0 ... bmp.height - 1
   for j in 0 ... bmp.width - 1
    rgb = bmp.getRGB(i, j)
    bmp.setRGB(i, j, rgb.getContrary)
   end
  end
 end

#Embossed effect
 The algorithm for #embossing is relatively complex, subtracting the RGB value of the current point from the RGB value of the adjacent points and adding 128 as the new RGB value. Since the color values of the adjacent points in the image are relatively close to each other, the
 # Therefore, after such an algorithm is processed, only the border area of the color, that is, the part of the neighboring color that is more different, will have a more obvious result, while the other smooth areas will have values close to 128 or so.
 #That is, gray, so that it has a relief effect.
 #In practice, some areas may still have "colored" dots or bars after this process, so it's best to do a grayscale process on the new RGB values.
 def self.emboss(bmp)

  preRGB=RGB.new(128, 128, 128)

  for i in 0 ... bmp.height - 1
   for j in 0 ... bmp.width - 1
    currentRGB=bmp.getRGB(i, j)
    r=(currentRGB.r - preRGB.r)*1+128
    g=(currentRGB.g - preRGB.g)*1+128
    b=(currentRGB.b-preRGB.b)*1+128

    bmp.setRGB(i, j, RGB.new(r,g,b).getGreyRGB)
    preRGB = currentRGB
   end
  end

 end