Sha256: fc49bb97f913f87483dd9a4b7732ff7b75533f1619294f6b3acb45892bdda5c5
Contents?: true
Size: 1.77 KB
Versions: 7
Compression:
Stored size: 1.77 KB
Contents
require 'exifr/tiff'
require 'delegate'
class FormatParser::EXIFParser
include FormatParser::IOUtils
# EXIFR kindly requests the presence of a few more methods than what our IOConstraint
# is willing to provide, but they can be derived from the available ones
class IOExt < SimpleDelegator
def readbyte
if byte = read(1)
byte.unpack('C').first
end
end
def seek(n, seek_mode = IO::SEEK_SET)
io = __getobj__
case seek_mode
when IO::SEEK_SET
io.seek(n)
when IO::SEEK_CUR
io.seek(io.pos + n)
when IO::SEEK_END
io.seek(io.size + n)
else
raise Errno::EINVAL
end
end
alias_method :getbyte, :readbyte
end
# Squash exifr's invalid date warning since we do not use that data.
logger = Logger.new(nil)
EXIFR.logger = logger
attr_accessor :exif_data, :orientation, :width, :height
ORIENTATIONS = [
:top_left,
:top_right,
:bottom_right,
:bottom_left,
:left_top,
:right_top,
:right_bottom,
:left_bottom
]
def initialize(io_blob_with_exif_data)
@exif_io = IOExt.new(io_blob_with_exif_data)
@exif_data = nil
@orientation = nil
@height = nil
@width = nil
end
def scan_image_tiff
raw_exif_data = EXIFR::TIFF.new(@exif_io)
# For things that we don't yet have a parser for
# we make the raw exif result available
@exif_data = raw_exif_data
@orientation = orientation_parser(raw_exif_data)
@width = @exif_data.width
@height = @exif_data.height
end
def orientation_parser(raw_exif_data)
value = raw_exif_data.orientation.to_i
@orientation = ORIENTATIONS[value - 1] if valid_orientation?(value)
end
def valid_orientation?(value)
(1..ORIENTATIONS.length).include?(value)
end
end
Version data entries
7 entries across 7 versions & 1 rubygems