Module: JXL

Defined in:
lib/jxl.rb,
lib/jxl/dct.rb,
lib/jxl/num.rb,
lib/jxl/image.rb,
lib/jxl/plane.rb,
lib/jxl/trace.rb,
lib/jxl/errors.rb,
lib/jxl/io/npy.rb,
lib/jxl/io/pam.rb,
lib/jxl/io/pfm.rb,
lib/jxl/io/pgx.rb,
lib/jxl/io/png.rb,
lib/jxl/io/ppm.rb,
lib/jxl/decoder.rb,
lib/jxl/encoder.rb,
lib/jxl/version.rb,
lib/jxl/bit/field.rb,
lib/jxl/frame/toc.rb,
lib/jxl/basic_info.rb,
lib/jxl/bit/reader.rb,
lib/jxl/bit/writer.rb,
lib/jxl/filter/epf.rb,
lib/jxl/color/gamut.rb,
lib/jxl/color/opsin.rb,
lib/jxl/color/ycbcr.rb,
lib/jxl/container/box.rb,
lib/jxl/color/transfer.rb,
lib/jxl/features/noise.rb,
lib/jxl/modular/stream.rb,
lib/jxl/render/blender.rb,
lib/jxl/vardct/decoder.rb,
lib/jxl/vardct/dequant.rb,
lib/jxl/entropy/decoder.rb,
lib/jxl/entropy/encoder.rb,
lib/jxl/filter/gaborish.rb,
lib/jxl/modular/decoder.rb,
lib/jxl/modular/ma_tree.rb,
lib/jxl/vardct/lf_group.rb,
lib/jxl/container/parser.rb,
lib/jxl/features/patches.rb,
lib/jxl/features/splines.rb,
lib/jxl/modular/weighted.rb,
lib/jxl/vardct/hf_global.rb,
lib/jxl/vardct/lf_global.rb,
lib/jxl/vardct/quantizer.rb,
lib/jxl/codestream/reader.rb,
lib/jxl/color/icc_profile.rb,
lib/jxl/headers/bit_depth.rb,
lib/jxl/modular/predictor.rb,
lib/jxl/modular/transform.rb,
lib/jxl/vardct/pass_group.rb,
lib/jxl/entropy/icc_stream.rb,
lib/jxl/render/orientation.rb,
lib/jxl/vardct/ac_strategy.rb,
lib/jxl/vardct/coeff_order.rb,
lib/jxl/container/signature.rb,
lib/jxl/entropy/hybrid_uint.rb,
lib/jxl/entropy/permutation.rb,
lib/jxl/entropy/prefix_code.rb,
lib/jxl/features/upsampling.rb,
lib/jxl/headers/size_header.rb,
lib/jxl/features/spot_colour.rb,
lib/jxl/headers/frame_header.rb,
lib/jxl/modular/group_header.rb,
lib/jxl/vardct/reconstructor.rb,
lib/jxl/headers/image_metadata.rb,
lib/jxl/headers/colour_encoding.rb,
lib/jxl/vardct/chroma_from_luma.rb,
lib/jxl/entropy/ans_distribution.rb,
lib/jxl/headers/custom_transform.rb,
lib/jxl/vardct/block_context_map.rb

Defined Under Namespace

Modules: Bit, Codestream, Color, Container, DCT, Entropy, Features, Filter, Headers, IO, Modular, Num, Render, Trace, VarDCT Classes: BasicInfo, CorruptError, Decoder, Encoder, Error, Event, FormatError, Frame, Image, InternalError, Plane, ResourceLimitError, SignatureError, TruncatedError, UnsupportedFeatureError

Constant Summary collapse

VERSION = 
"1.0.0"

Class Method Summary collapse

Class Method Details

.decode(data, pixel_format: :native, color_space: :original, desired_scale: 1, max_pixels: 100_000_000, max_memory: 2 << 30, strict: true, apply_orientation: true, render_spot_colors: true) ⇒ Object

Decodes a JPEG XL codestream or container into an Image.



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# File 'lib/jxl.rb', line 84

def decode(data, pixel_format: :native, color_space: :original, desired_scale: 1,
           max_pixels: 100_000_000, max_memory: 2 << 30, strict: true,
           apply_orientation: true, render_spot_colors: true) # rubocop:disable Metrics/AbcSize,Metrics/CyclomaticComplexity,Metrics/ParameterLists
  validate_options!(pixel_format, color_space, desired_scale)
  frames = Codestream::Reader.new(data, max_pixels:).read_all_headers
  enforce_memory_limit!(frames.first.basic_info, max_memory)
  references = Array.new(4)
  dc_frames = Array.new(4)
  output = nil
  displayed = []
  frames.each do |parsed|
    frame = parsed.frame_header
    raw = if frame.encoding == :vardct
            VarDCT::Decoder.decode(parsed, references:, dc_frames:)
          else
            Modular::Decoder.decode_parsed(parsed, render: true, references:)
          end
    if frame.type == 1
      dc_frames[frame.dc_level - 1] = raw
      next
    end
    image = frame.encoding == :modular ? convert_modular_colour(raw, parsed) : raw
    if frame.type == 2
      references[frame.save_as_reference] = frame.save_before_colour_transform ? raw : image
    else
      composed = Render::Blender.compose(image, frame, references, parsed.basic_info.width, parsed.basic_info.height)
      if !frame.last && (frame.duration.zero? || !frame.save_as_reference.zero?)
        references[frame.save_as_reference] = frame.save_before_colour_transform ? raw : composed
      end
      rendered = render_spot_colors ? Features::SpotColour.apply(composed) : composed
      output = apply_orientation ? Render::Orientation.apply(rendered) : rendered
      if !frame.duration.zero? || frame.last
        displayed << Frame.new(planes: output.channels, duration: frame.duration, timecode: frame.timecode,
                               name: frame.name, blend_info: frame.blend)
      end
    end
  end
  output ||= raise(CorruptError, "codestream has no display frame")
  encoding = frames.first.basic_info.metadata.colour_encoding
  profile = if encoding.want_icc && frames.first.frame_header.colour_transform == :xyb
              Color::ICCProfile.create(encoding.with(want_icc: false, transfer_function: 8))
            else
              frames.first.icc_profile || Color::ICCProfile.create(encoding)
            end
  output = output.with(frames: displayed.freeze, icc_profile: profile)
  output = convert_output_colour(output, color_space)
  output = downsample(output, desired_scale) unless desired_scale == 1
  validate_samples!(output, strict)
end

.encode(image) ⇒ Object

Encodes an image as a lossless Modular JPEG XL codestream.



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# File 'lib/jxl.rb', line 78

def encode(image, **) = Encoder.new(image, **).encode

.info(data) ⇒ Object

Reads basic image metadata without decoding pixels.



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# File 'lib/jxl.rb', line 81

def info(data, **) = BasicInfo.read(data, **)