Matrix bitwise 'and' of two images.

Example

iex> use Image.Math
iex> image = Image.new!(2, 2, color: [10, 20, 30])
iex> Image.get_pixel!(image &&& image, 0, 0)
[10, 20, 30]

Matrix exponent of two images or one image and a constant or vector.

Delegates to Kernel.**/2 if none of the parameters is a Vix.Vips.Image.t/0.

Example

iex> use Image.Math
iex> image = Image.new!(2, 2, color: [10, 20, 30])
iex> Image.get_pixel!(image ** 2, 0, 0)
[100.0, 400.0, 900.0]

Matrix multiplation of two images or one image and a constant or vector.

Delegates to Kernel.*/2 if none of the parameters is a Vix.Vips.Image.t/0.

Example

iex> use Image.Math
iex> image = Image.new!(2, 2, color: [10, 20, 30])
iex> Image.get_pixel!(image * 2, 0, 0)
[20.0, 40.0, 60.0]

Matrix addition of two images or one image and a constant or vector.

Delegates to Kernel.+/2 if none of the parameters is a Vix.Vips.Image.t/0.

Example

iex> use Image.Math
iex> image = Image.new!(2, 2, color: [10, 20, 30])
iex> Image.get_pixel!(image + 5, 0, 0)
[15.0, 25.0, 35.0]

Matrix unary minues of an image or a number.

Example

iex> use Image.Math
iex> image = Image.new!(2, 2, color: [10, 20, 30])
iex> Image.get_pixel!(-image, 0, 0)
[-10.0, -20.0, -30.0]

Matrix subtraction of two images or one image and a constant or vector.

Delegates to Kernel.-/2 if none of the parameters is a Vix.Vips.Image.t/0.

Example

iex> use Image.Math
iex> image = Image.new!(2, 2, color: [10, 20, 30])
iex> Image.get_pixel!(image - 5, 0, 0)
[5.0, 15.0, 25.0]

Matrix division of two images or one image and a constant or vector.

Delegates to Kernel.//2 if none of the parameters is a Vix.Vips.Image.t/0.

Example

iex> use Image.Math
iex> image = Image.new!(2, 2, color: [10, 20, 30])
iex> Image.get_pixel!(image / 2, 0, 0)
[5.0, 10.0, 15.0]

Matrix inequality of two images or one image and a constant or vector.

Delegates to Kernel.!=/2 if none of the parameters is a Vix.Vips.Image.t/0.

Example

iex> use Image.Math
iex> image = Image.new!(2, 2, color: [10, 20, 30])
iex> Image.get_pixel!(image != [10, 20, 30], 0, 0)
[0, 0, 0]

Matrix less than of two images or one image and a constant or vector.

Delegates to Kernel.</2 if none of the parameters is a Vix.Vips.Image.t/0.

Example

iex> use Image.Math
iex> image = Image.new!(2, 2, color: [10, 20, 30])
iex> Image.get_pixel!(image < 20, 0, 0)
[255, 0, 0]

Matrix bitwise 'left shift' of two images.

Example

iex> use Image.Math
iex> image = Image.new!(2, 2, color: [10, 20, 30])
iex> one = Image.new!(2, 2, color: [1, 1, 1])
iex> Image.get_pixel!(image <<< one, 0, 0)
[20, 40, 60]

Matrix less than or equal of two images or one image and a constant or vector.

Delegates to Kernel.<=/2 if none of the parameters is a Vix.Vips.Image.t/0.

Example

iex> use Image.Math
iex> image = Image.new!(2, 2, color: [10, 20, 30])
iex> Image.get_pixel!(image <= 20, 0, 0)
[255, 255, 0]

Matrix equality of two images or one image and a constant or vector.

Delegates to Kernel.==/2 if none of the parameters is a Vix.Vips.Image.t/0.

Example

iex> use Image.Math
iex> image = Image.new!(2, 2, color: [10, 20, 30])
iex> Image.get_pixel!(image == [10, 20, 30], 0, 0)
[255, 255, 255]

Matrix greater than of two images or one image and a constant or vector.

Delegates to Kernel.>/2 if none of the parameters is a Vix.Vips.Image.t/0.

Example

iex> use Image.Math
iex> image = Image.new!(2, 2, color: [10, 20, 30])
iex> Image.get_pixel!(image > 20, 0, 0)
[0, 0, 255]

Matrix greater than or equal of two images or one image and a constant or vector.

Delegates to Kernel.>=/2 if none of the parameters is a Vix.Vips.Image.t/0.

Example

iex> use Image.Math
iex> image = Image.new!(2, 2, color: [10, 20, 30])
iex> Image.get_pixel!(image >= 20, 0, 0)
[0, 255, 255]

Matrix bitwise 'right shift' of two images.

Example

iex> use Image.Math
iex> image = Image.new!(2, 2, color: [10, 20, 30])
iex> one = Image.new!(2, 2, color: [1, 1, 1])
iex> Image.get_pixel!(image >>> one, 0, 0)
[5, 10, 15]

@spec bottom_n(image :: Vix.Vips.Image.t(), n :: non_neg_integer()) ::
  {minimim :: float(), x_max :: non_neg_integer(), y_max :: non_neg_integer(),
   max_coordinates :: [Image.point(), ...]}

Return the bottom n image minima.

The function returns the coordinates of:n smallest values of the image.

Arguments

• image is any Vix.Vips.Image.t/0.

• n is the number of minima to find. The default is 10. Minima in this case means the smallest n values; They may not be equal to the minimum.

Returns

• {minimum, x_min, y_min, [{x, y}, ...])

Example

iex> {:ok, image} = Vix.Vips.Image.new_from_list([[1, 2], [3, 4]])
iex> {minimum, x_min, y_min, _coordinates} = Image.Math.bottom_n(image, 2)
iex> {minimum, x_min, y_min}
{1.0, 0, 0}

Guards if a given value might be reasonably interpreted as a pixel.

@spec maxpos(image :: Vix.Vips.Image.t(), n :: non_neg_integer()) ::
  {maximum :: number(), max_coordinates :: [Image.point(), ...],
   maybe_overflow :: :maybe_overflow | nil}

Return the image maxima.

This function retrieves the coordinates of the n largest values then then filters them to return only those coordinates that have the maximum value.

Arguments

• image is any Vix.Vips.Image.t/0.

• n is the number of maxima to find. The default is 10. Maxima in this case means those values that exactly match the maximum value.

Returns

• {maximum, [{x, y}, ...], maybe_overflow). If maybe_overflow is set to :maybe_overflow its an indication that the number of coordinates is the same as the requested n. Therefore it is possible - maybe even likely - that there are other coordinates that have the maximum value but have not been returned.

Example

This example draws a red image with a single green pixel. We then look for all the coordinates that have a green pixel.

iex> {:ok, image} =
iex>   Image.new!(5, 5, color: :red)
iex>   |> Image.mutate(fn i -> Image.Draw.point!(i, 2, 2, color: [0,255,0]) end)
iex> image
iex> |> Image.Math.==([0, 255, 0])
iex> |> Image.band_and!()
iex> |> Image.Math.maxpos()
{255, [{2, 2}], nil}

# Since all pixels are red and we want
# the coordinates of all the red pixels
# we have an overlow: We retrieve only 3
# maxima and they are all red. Perhaps
# the red of the image pixels are also red?
# Yes - they are!
iex> Image.new!(2, 2, color: :red)
iex> |> Image.Math.==([255, 0, 0])
iex> |> Image.band_and!()
iex> |> Image.Math.maxpos(3)
{255, [{0, 1}, {1, 0}, {0, 0}], :maybe_overflow}

@spec minpos(image :: Vix.Vips.Image.t(), n :: non_neg_integer()) ::
  {maximum :: number(), max_coordinates :: [Image.point(), ...],
   maybe_overflow :: :maybe_overflow | nil}

Return the image minima.

This function retrieves the coordinates of the n smallest values then then filters them to return only those coordinates that have the minimum value.

Arguments

• image is any Vix.Vips.Image.t/0.

• n is the number of minima to find. The default is 10. Minima in this case means those values that exactly match the minimum value.

Returns

• {minimum, [{x, y}, ...], maybe_overflow). If maybe_overflow is set to :maybe_overflow its an indication that the number of coordinates is the same as the requested n. Therefore it is possible - maybe even likely - that there are other coordinates that have the minimum value but have not been returned.

Example

iex> {:ok, image} = Vix.Vips.Image.new_from_list([[1, 2], [3, 4]])
iex> Image.Math.minpos(image, 2)
{1.0, [{0, 0}], nil}

@spec top_n(image :: Vix.Vips.Image.t(), n :: non_neg_integer()) ::
  {maximum :: float(), x_max :: non_neg_integer(), y_max :: non_neg_integer(),
   max_coordinates :: [Image.point(), ...]}

Return the top n image maxima.

The function returns the coordinates of:n largest values of the image.

Arguments

• image is any Vix.Vips.Image.t/0.

• n is the number of maxima to find. The default is 10. Maxima in this case means the largest n values; They may not be equal to the maximum.

Returns

• {maximum, x_max, y_max, [{x, y}, ...])

Example

iex> {:ok, image} = Vix.Vips.Image.new_from_list([[1, 2], [3, 4]])
iex> {maximum, x_max, y_max, _coordinates} = Image.Math.top_n(image, 2)
iex> {maximum, x_max, y_max}
{4.0, 1, 1}

Matrix bitwise 'or' of two images.

Example

iex> use Image.Math
iex> image = Image.new!(2, 2, color: [10, 20, 30])
iex> Image.get_pixel!(image ||| image, 0, 0)
[10, 20, 30]