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Versions: 6
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Stored size: 1.47 KB
Contents
class PSD
module ImageFormat
# Parses an RLE compressed image
module RLE
private
def parse_rle!
@byte_counts = parse_byte_counts!
parse_channel_data!
end
def parse_byte_counts!
byte_counts = []
(channels * height).times do |i|
byte_counts << @file.read_short
end
return byte_counts
end
def parse_channel_data!
@chan_pos = 0
@line_index = 0
channels.times do |i|
PSD.logger.debug "Parsing RLE channel ##{i}: file position = #{@file.tell}, image position = #{@chan_pos}, line = #{@line_index}"
decode_rle_channel
@line_index += height
end
end
def decode_rle_channel
height.times do |j|
byte_count = @byte_counts[@line_index + j]
finish = @file.tell + byte_count
while @file.tell < finish
len = @file.read(1).bytes.to_a[0]
if len < 128
len += 1
(@chan_pos...@chan_pos+len).each do |k|
@channel_data[k] = @file.read(1).bytes.to_a[0]
end
@chan_pos += len
elsif len > 128
len ^= 0xff
len += 2
val = @file.read(1).bytes.to_a[0]
(@chan_pos...@chan_pos+len).each do |k|
@channel_data[k] = val
end
@chan_pos += len
end
end
end
end
end
end
end
Version data entries
6 entries across 6 versions & 2 rubygems