PaperForge.Images.JPEG (PaperForge v0.2.0)

Reads JPEG metadata without decoding image pixels.

The JPEG binary can be embedded directly in the PDF using /DCTDecode.

Summary

Types

color_space()

error_reason()

metadata()

Functions

jpeg?(arg1)

Returns whether a binary begins with the JPEG start-of-image marker.

parse(arg1)

Reads JPEG metadata.

parse!(data)

Reads JPEG metadata and raises when the binary is invalid.

Types

color_space()

@type color_space() :: :device_gray | :device_rgb | :device_cmyk

error_reason()

@type error_reason() ::
  :invalid_jpeg
  | :missing_start_of_frame
  | :truncated_marker
  | :truncated_segment
  | :invalid_segment_length
  | :invalid_start_of_frame
  | {:unsupported_components, non_neg_integer()}

metadata()

@type metadata() :: %{
  width: pos_integer(),
  height: pos_integer(),
  bits_per_component: pos_integer(),
  components: pos_integer(),
  color_space: color_space()
}

Functions

jpeg?(arg1)

@spec jpeg?(binary()) :: boolean()

Returns whether a binary begins with the JPEG start-of-image marker.

parse(arg1)

@spec parse(binary()) :: {:ok, metadata()} | {:error, error_reason()}

Reads JPEG metadata.

parse!(data)

@spec parse!(binary()) :: metadata()

Reads JPEG metadata and raises when the binary is invalid.