The StbImage struct.

It has the following fields:

• :data - a blob with the image bytes in HWC (heigth-width-channels) order
• :shape - a tuple with the {height, width, channels}
• :type - the type unit in the binary ({:u, 8} or {:f, 32})

The number of channels correlates directly to the color mode. 1 channel is greyscale, 2 is greyscale+alpha, 3 is RGB, and 4 is RGB+alpha.

Creates a StbImage from a Nx tensor.

The tensor is expected to have the shape {h, w, c} and one of the supported types (u8/f32).

Creates a StbImage directly.

data is a binary blob with the image bytes in HWC (heigth-width-channels) order. shape is a tuple with the heigth, width, and channel dimensions.

Options

• :type - The type of the data. Defaults to {:u, 8}. Must be one of {:u, 8} or {:f, 32}. The :u8 and :f32 convenience atom syntax is also available.

Reads image from binary representing an image.

Options

• :channels - The number of desired channels. Use 0 for auto-detection. Defaults to 0.

Example

{:ok, buffer} = File.read("/path/to/image")
{:ok, img} = StbImage.read_binary(buffer)
{h, w, c} = img.shape
img = img.data

# If you know that the image is a 4-channel image and auto-detection failed
{:ok, img} = StbImage.read_binary(buffer, channels: 4)
{h, w, c} = img.shape
img = img.data

Raising version of read_binary/2.

Reads image from file at path.

Options

• :channels - The number of desired channels. Use 0 for auto-detection. Defaults to 0.

Example

{:ok, img} = StbImage.read_file("/path/to/image")
{h, w, c} = img.shape
data = img.data

# If you know that the image is a 4-channel image and auto-detection failed
{:ok, img} = StbImage.read_file("/path/to/image", channels: 4)
{h, w, c} = img.shape
img = img.data

Raising version of read_file/2.

Decodes GIF image from a binary representing a GIF.

Example

{:ok, buffer} = File.read("/path/to/image")
{:ok, frames, delays} = StbImage.read_gif_binary(buffer)
frame = Enum.at(frames, 0)
{h, w, 3} = frame.shape

Reads GIF image from file at path.

Example

{:ok, frames, delays} = StbImage.read_gif_file("/path/to/image")
frame = Enum.at(frames, 0)
{h, w, 3} = frame.shape

Resizes the image into the given output_h and output_w.

Example

img = StbImage.new(raw_img, {h, w, channels})
StbImage.resize(raw_img, div(h, 2), div(w, 2))

Encodes image to a binary.

The supported formats are :jpg, :png, :bmp, :tga, :hdr.

Example

img = StbImage.new(raw_img, {h, w, channels})
binary = StbImage.to_binary(img, :png)

Converts a StbImage to a Nx tensor.

It accepts the same options as Nx.from_binary/3.

Writes image to the file at path.

The supported formats are :jpg, :png, :bmp, :tga, :hdr.

The format is determined from the file extension, if possible. You can also pass it explicitly via the :format option.

Returns :ok on success and {:error, reason} otherwise.

Make sure the directory you intend to write the file to exists. Otherwise, an error is returned.

Options

• :format - one of the supported image formats

Raising version of write_file/3.