module BMP::Utils
Public Instance Methods
calc_file_size(img_size, header_size=BMP::HEADER_SIZE)
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@return [Integer]
# File lib/bmp/utils.rb, line 20 def calc_file_size(img_size, header_size=BMP::HEADER_SIZE) img_size + header_size end
calc_image_data_size(arg_width, arg_height)
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@return [Integer]
# File lib/bmp/utils.rb, line 7 def calc_image_data_size(arg_width, arg_height) ((BMP::BITS_PER_PIXEL * arg_width ) / 32.0).ceil * 4 * arg_height end
int_to_octets_string_endian_little(int)
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# File lib/bmp/utils.rb, line 11 def int_to_octets_string_endian_little(int) [int].pack("V").each_byte.map {|b| b.to_s(16).rjust(2, '0')}.join(':') end
octets_string_endian_little_to_int(octets_str)
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# File lib/bmp/utils.rb, line 15 def octets_string_endian_little_to_int(octets_str) octets_str.split(':').map {|o| o.to_i(16).chr}.join.unpack('V').first end
parse_image(img_in)
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# File lib/bmp/utils.rb, line 45 def parse_image(img_in) img_width = img_in.width img_height = img_in.height img_data_size = calc_image_data_size(img_width, img_height) img_file_size = calc_file_size(img_data_size) img_pixels = pixel_array_template(img_width, img_height) img_height.times do |row| img_width.times do |col| rgba = ChunkyPNG::Color.to_hex(img_in.get_pixel(row,col), true)[1..-1] rr, gg, bb, aa = rgba.scan(/../) img_pixels[col][row] = [bb,gg,rr,aa].join #puts row.to_s + ',' + col.to_s + ' => ' + rgba.inspect if @debug end end hash = {} hash[:file_size] = img_file_size hash[:image_size] = img_data_size hash[:image_width] = img_width hash[:image_height] = img_height hash[:pixel_array] = write_pixel_array(img_pixels) hash end
pixel_array_template(arg_width, arg_height)
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# File lib/bmp/utils.rb, line 24 def pixel_array_template(arg_width, arg_height) Array.new(arg_height) {Array.new(arg_width) {nil}} end
pixel_binstring(rgba_string)
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# File lib/bmp/utils.rb, line 40 def pixel_binstring(rgba_string) raise ArgumentError unless rgba_string =~ /\A\h{8}\z/ [rgba_string].pack("H*") end
write_pixel_array(img_px)
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# File lib/bmp/utils.rb, line 28 def write_pixel_array(img_px) str = '' img_px.reverse_each do |row| row.each do |color| str << pixel_binstring(color) end end return str end