Image.BandFormat (image v0.73.0)

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Functions to define and validate the band formats of an image.

Summary

Types

t()

Functions

image_format_from_nx(tensor)

Returns the Image format type for an Nx format type.

known_band_formats()

Returns a list of the known band formats.

nx_format(image)

Returns the Nx format type for an Image or image format type.

nx_format!(image_or_format)

Returns the Nx format type for an Image or image format type or raises an exception.

validate(format)

Validates a band format returning the band format value required in the underlying Vix code.

Types

t()

@type t() ::
  {:u, 8}
  | {:s, 8}
  | {:u, 16}
  | {:s, 16}
  | {:u, 32}
  | {:s, 32}
  | {:u, 64}
  | {:s, 64}
  | {:f, 32}
  | {:f, 64}

Functions

image_format_from_nx(tensor)

Returns the Image format type for an Nx format type.

Image uses the same type formats as Nx so this function is more a validation than a conversion.

Arguments

  • nx_type is any Nx type, such as {:u, 8}.

Returns

  • {:ok, band_format} or

  • {:error, reason}.

Examples

iex> Image.BandFormat.image_format_from_nx({:u, 8})
{:ok, :VIPS_FORMAT_UCHAR}

iex> Image.BandFormat.image_format_from_nx({:u, 16})
{:ok, :VIPS_FORMAT_USHORT}

known_band_formats()

Returns a list of the known band formats.

nx_format(image)

Returns the Nx format type for an Image or image format type.

Image uses the same type formats as Nx so this function is more a validation than a conversion.

Arguments

Returns

  • {:ok, band_format} or

  • {:error, reason}.

Examples

iex> Image.BandFormat.nx_format(:VIPS_FORMAT_UCHAR)
{:ok, {:u, 8}}

iex> image = Image.new!(2, 2, color: :red)
iex> Image.BandFormat.nx_format(image)
{:ok, {:u, 8}}

nx_format!(image_or_format)

Returns the Nx format type for an Image or image format type or raises an exception.

Image uses the same type formats as Nx so this function is more a validation than a conversion.

Arguments

Returns

  • band_format or

  • raises an exception.

Examples

iex> Image.BandFormat.nx_format!(:VIPS_FORMAT_USHORT)
{:u, 16}

iex> image = Image.new!(2, 2, color: :red)
iex> Image.BandFormat.nx_format!(image)
{:u, 8}

validate(format)

Validates a band format returning the band format value required in the underlying Vix code.

Arguments

Returns

  • {:ok, validated_foramt} or

  • {:error, reason}

Examples

  iex> Image.BandFormat.validate({:u, 8})
  {:ok, :VIPS_FORMAT_UCHAR}

  iex> Image.BandFormat.validate(:u8)
  {:ok, :VIPS_FORMAT_UCHAR}

  iex> Image.BandFormat.validate(:VIPS_FORMAT_UCHAR)
  {:ok, :VIPS_FORMAT_UCHAR}