class PDF::Reader::Filter::Depredict

def filter(data)


preprocessing
Streams can be preprocessed to improve compression. This reverses the
############################################################################### 
def filter(data)
  predictor = @options[:Predictor].to_i
  case predictor
  when 0, 1 then
    data
  when 2    then
    tiff_depredict(data)
  when 10, 11, 12, 13, 14, 15 then
    png_depredict(data)
  else
    raise  MalformedPDFError, "Unrecognised predictor value (#{predictor})"
  end
end