Files
danbooru/lib/imagesize/lib/image_size.rb
2012-01-27 15:05:46 -05:00

298 lines
8.3 KiB
Ruby
Executable File

#!ruby
# encoding: US-ASCII
class ImageSize
require "stringio"
# Image Type Constants
module Type
OTHER = "OTHER"
GIF = "GIF"
PNG = "PNG"
JPEG = "JPEG"
BMP = "BMP"
PPM = "PPM" # PPM is like PBM, PGM, & XV
PBM = "PBM"
PGM = "PGM"
# XV = "XV"
XBM = "XBM"
TIFF = "TIFF"
XPM = "XPM"
PSD = "PSD"
SWF = "SWF"
end
JpegCodeCheck = [
"\xc0", "\xc1", "\xc2", "\xc3",
"\xc5", "\xc6", "\xc7",
"\xc9", "\xca", "\xcb",
"\xcd", "\xce", "\xcf",
]
# image type list
def ImageSize.type_list
Type.constants
end
# receive image & make size
# argument 1 is image String, StringIO or IO
# argument 2 is type(ImageSize::Type::GIF and so on.) or nil
def initialize(img_data, img_type = nil)
@img_data = img_data.dup
@img_width = nil
@img_height = nil
@img_type = nil
if @img_data.is_a?(IO)
img_top = @img_data.read(1024)
img_io = def_read_o(@img_data)
elsif @img_data.is_a?(StringIO)
img_top = @img_data.read(1024)
img_io = def_read_o(@img_data)
elsif @img_data.is_a?(String)
img_top = @img_data[0, 1024]
# img_io = StringIO.open(@img_data){|sio| io = def_read_o(sio); io }
img_io = StringIO.open(@img_data)
img_io = def_read_o(img_io)
else
raise "argument class error!! #{img_data.type}"
end
if @img_type.nil?
@img_type = check_type(img_top)
else
type = Type.constants.find{|t| img_type == t }
raise("type is failed. #{img_type}\n") if !type
@img_type = img_type
end
if @img_type != Type::OTHER
@img_width, @img_height = self.__send__("measure_#{@img_type}", img_io)
else
@img_width, @img_height = [nil, nil]
end
if @img_data.is_a?(String)
img_io.close
end
end
# get image type
# ex. "GIF", "PNG", "JPEG"
def get_type; @img_type; end
# get image height
def get_height
if @img_type == Type::OTHER then nil else @img_height end
end
# get image width
def get_width
if @img_type == Type::OTHER then nil else @img_width end
end
# get image width and height(Array)
def get_size
[self.get_width, self.get_height]
end
alias :height :get_height
alias :h :get_height
alias :width :get_width
alias :w :get_width
alias :size :get_size
private
# define read_o
def def_read_o(io)
io.seek(0, 0)
# define Singleton-method definition to IO (byte, offset)
def io.read_o(length = 1, offset = nil)
self.seek(offset, 0) if offset
ret = self.read(length)
raise "cannot read!!" unless ret
ret
end
io
end
def check_type(img_top)
if img_top =~ /^GIF8[7,9]a/ then Type::GIF
elsif img_top[0, 8] == "\x89PNG\x0d\x0a\x1a\x0a" then Type::PNG
elsif img_top[0, 2] == "\xFF\xD8" then Type::JPEG
elsif img_top[0, 2] == 'BM' then Type::BMP
elsif img_top =~ /^P[1-7]/ then Type::PPM
elsif img_top =~ /\#define\s+\S+\s+\d+/ then Type::XBM
elsif img_top[0, 4] == "MM\x00\x2a" then Type::TIFF
elsif img_top[0, 4] == "II\x2a\x00" then Type::TIFF
elsif img_top =~ /\/\* XPM \*\// then Type::XPM
elsif img_top[0, 4] == "8BPS" then Type::PSD
elsif img_top[1, 2] == "WS" then Type::SWF
else Type::OTHER
end
end
def measure_GIF(img_io)
img_io.read_o(6)
img_io.read_o(4).unpack('vv')
end
def measure_PNG(img_io)
img_io.read_o(12)
raise "This file is not PNG." unless img_io.read_o(4) == "IHDR"
img_io.read_o(8).unpack('NN')
end
def measure_JPEG(img_io)
c_marker = "\xFF" # Section marker.
img_io.read_o(2)
while(true)
marker, code, length = img_io.read_o(4).unpack('aan')
raise "JPEG marker not found!" if marker != c_marker
if JpegCodeCheck.include?(code)
height, width = img_io.read_o(5).unpack('xnn')
return([width, height])
end
img_io.read_o(length - 2)
end
end
def measure_BMP(img_io)
img_io.read_o(26).unpack("x18VV");
end
def measure_PPM(img_io)
header = img_io.read_o(1024)
header.gsub!(/^\#[^\n\r]*/m, "")
header =~ /^(P[1-6])\s+?(\d+)\s+?(\d+)/m
width = $2.to_i; height = $3.to_i
case $1
when "P1", "P4" then @img_type = "PBM"
when "P2", "P5" then @img_type = "PGM"
when "P3", "P6" then @img_type = "PPM"
# when "P7"
# @img_type = "XV"
# header =~ /IMGINFO:(\d+)x(\d+)/m
# width = $1.to_i; height = $2.to_i
end
[width, height]
end
alias :measure_PGM :measure_PPM
alias :measure_PBM :measure_PPM
def measure_XBM(img_io)
img_io.read_o(1024) =~ /^\#define\s*\S*\s*(\d+)\s*\n\#define\s*\S*\s*(\d+)/mi
[$1.to_i, $2.to_i]
end
def measure_XPM(img_io)
width = height = nil
while(line = img_io.read_o(1024))
if line =~ /"\s*(\d+)\s+(\d+)(\s+\d+\s+\d+){1,2}\s*"/m
width = $1.to_i; height = $2.to_i
break
end
end
[width, height]
end
def measure_PSD(img_io)
img_io.read_o(26).unpack("x14NN")
end
def measure_TIFF(img_io)
endian = if (img_io.read_o(4) =~ /II\x2a\x00/o) then 'v' else 'n' end
# 'v' little-endian 'n' default to big-endian
packspec = [
nil, # nothing (shouldn't happen)
'C', # BYTE (8-bit unsigned integer)
nil, # ASCII
endian, # SHORT (16-bit unsigned integer)
endian.upcase, # LONG (32-bit unsigned integer)
nil, # RATIONAL
'c', # SBYTE (8-bit signed integer)
nil, # UNDEFINED
endian, # SSHORT (16-bit unsigned integer)
endian.upcase, # SLONG (32-bit unsigned integer)
]
offset = img_io.read_o(4).unpack(endian.upcase)[0] # Get offset to IFD
ifd = img_io.read_o(2, offset)
num_dirent = ifd.unpack(endian)[0] # Make it useful
offset += 2
num_dirent = offset + (num_dirent * 12); # Calc. maximum offset of IFD
ifd = width = height = nil
while(width.nil? || height.nil?)
ifd = img_io.read_o(12, offset) # Get first directory entry
break if (ifd.nil? || (offset > num_dirent))
offset += 12
tag = ifd.unpack(endian)[0] # ...and decode its tag
type = ifd[2, 2].unpack(endian)[0] # ...and the data type
# Check the type for sanity.
next if (type > packspec.size + 0) || (packspec[type].nil?)
if tag == 0x0100 # Decode the value
width = ifd[8, 4].unpack(packspec[type])[0]
elsif tag == 0x0101 # Decode the value
height = ifd[8, 4].unpack(packspec[type])[0]
end
end
raise "#{if width.nil? then 'width not defined.' end} #{if height.nil? then 'height not defined.' end}" if width.nil? || height.nil?
[width, height]
end
def measure_SWF(img_io)
header = img_io.read_o(9)
sig1 = header[0,1]
sig2 = header[1,1]
sig3 = header[2,1]
if !((sig1 == 'F' || sig1 == 'C') && sig2 == 'W' && sig3 == 'S')
raise("This file is not SWF.")
end
bit_length = Integer("0b#{header.unpack('@8B5')[0]}")
header << img_io.read_o(bit_length*4/8+1)
str = header.unpack("@8B#{5+bit_length*4}")[0]
last = 5
x_min = Integer("0b#{str[last,bit_length]}")
x_max = Integer("0b#{str[(last += bit_length),bit_length]}")
y_min = Integer("0b#{str[(last += bit_length),bit_length]}")
y_max = Integer("0b#{str[(last += bit_length),bit_length]}")
width = (x_max - x_min)/20
height = (y_max - y_min)/20
width *= -1 if width < 0
height *= -1 if height < 0
[width, height]
end
end
if __FILE__ == $0
print "TypeList: #{ImageSize.type.inspect}\n"
Dir.glob("*").each do |file|
print "#{file} (string)\n"
open(file, "rb") do |fh|
img = ImageSize.new(fh.read)
print <<-EOF
type: #{img.get_type.inspect}
width: #{img.get_width.inspect}
height: #{img.get_height.inspect}
EOF
end
end
end